We investigate strongly gravitationally lensed type II supernovae (LSNe II) for time-delay cosmography, incorporating microlensing effects; this expands on previous microlensing studies of type Ia supernovae (SNe Ia). We use the radiative-transfer code TARDIS to recreate five spectra of the prototypical SN 1999em at different times within the plateau phase of the light curve. The microlensing-induced deformations of the spectra and light curves are calculated by placing the SN into magnification maps generated with the code GERLUMPH. We study the impact of microlensing on the color curves and find that there is no strong influence on them during the investigated time interval of the plateau phase. The color curves are only weakly affected by microlensing due to the almost achromatic behavior of the intensity profiles. However, the lack of nonlinear structure in the color curves during the plateau phase of type II-plateau supernovae makes time-delay measurements more challenging compared to SN Ia color curves, given the possible presence of differential dust extinction. Therefore, we further investigate SN phase inference through spectral absorption lines under the influence of microlensing and Gaussian noise. As the spectral features shift to longer wavelengths with progressing time after explosion, the measured wavelength of a specific absorption line provides information on the epoch of the SN. The comparison between retrieved epochs of two observed lensing images then gives the time delay of the images. We find that the phase retrieval method that uses spectral features yields accurate delays with uncertainties of ≲2 days, making it a promising approach.

Time-delay strong lensing (TDSL) is a powerful probe of the current expansion rate of the Universe. However, in light of the discrepancies between early and late-time cosmological studies, efforts revolve around the characterisation of systematic uncertainties in the methods. Here, we focus on the mass-sheet degeneracy (MSD), which is considered a significant source of systematics in TDSL, and aim to assess the constraining power provided by IFU stellar kinematics. We approximate the MSD with a cored, two-parameter extension to the lensing mass profiles (with core radius $r_{\rm c}$ and mass-sheet parameter $\lambda_{\rm int}$). In addition, we utilise mock IFU stellar kinematics of time-delay strong lenses, given the prospects of obtaining such data with JWST. We construct joint strong lensing and stellar dynamical models, where the time delays, mock imaging and IFU observations are used to constrain the mass profile of lens galaxies, and yield joint constraints on the time-delay distance ($D_{\Delta t}$) and angular diameter distance ($D_{\rm d}$) to the lens. We find that mock JWST-like stellar kinematics constrain the internal mass sheet and limit its contribution to the uncertainties of $D_{\Delta t}$ and $D_{\rm d}$, each at the < 4% level, without assumptions on the background cosmological model. These distance constraints would translate to a < 4% precision measurement on $H_{\rm 0}$ in flat $\Lambda CDM$ for a single lens. Our study shows that IFU stellar kinematics of time-delay strong lenses will be key in lifting the MSD on a per lens basis, assuming reasonable core sizes. However, even in the limit of infinite $r_{\rm c}$, where $D_{\Delta t}$ is degenerate with $\lambda_{\rm int}$, stellar kinematics of the deflector, time delays and imaging data will provide powerful constraints on $D_{\rm d}$, which becomes the dominant source of information in the cosmological inference.

The impact of new and highly precise neutron β decay data is reviewed. We focus on recent results from neutron lifetime, β asymmetry, and electron-neutrino correlation experiments. From these results, weak interaction parameters are extracted with unprecedented precision, which is possible also because of progress in effective field theory and lattice QCD. Limits on New Physics beyond the Standard Model derived from neutron decay data are sharper than those derived from high-energy experiments, except for processes involving right-handed neutrinos.

SU(2) gauge fields coupled to an axion field can acquire an isotropic background solution during inflation. We study homogeneous but anisotropic inflationary solutions in the presence of such (massless) gauge fields. A gauge field in the cosmological background may pose a threat to spatial isotropy. We show, however, that such models generally isotropize in Bianchi type-I geometry, and the isotropic solution is the attractor. Restricting the setup by adding an axial symmetry, we revisited the numerical analysis presented in [1]. We find that the reported numerical breakdown in the previous analysis is an artifact of parametrization singularity. We use a new parametrization that is well-defined all over the phase space. We show that the system respects the cosmic no-hair conjecture and the anisotropies always dilute away within a few e-folds.

Ghost-free bimetric theory describes two nonlinearly interacting spin-2 fields, one massive and one massless, thus extending general relativity. We confront bimetric theory with observations of Supernovae type 1a, Baryon Acoustic Oscillations and the Cosmic Microwave Background in a statistical analysis, utilising the recently proposed physical parametrisation. This directly constrains the physical parameters of the theory, such as the mass of the spin-2 field and its coupling to matter. We find that all models under consideration are in agreement with the data. Next, we compare these results to bounds from local tests of gravity. Our analysis reveals that all two- and three parameter models are observationally consistent with both cosmological and local tests of gravity. The minimal bimetric model (only β₁) is ruled out by our combined analysis.

Numerical methods have become a powerful tool for research in astrophysics, but their utility depends critically on the availability of suitable simulation codes. This calls for continuous efforts in code development, which is necessitated also by the rapidly evolving technology underlying today's computing hardware. Here we discuss recent methodological progress in the GADGET code, which has been widely applied in cosmic structure formation over the past two decades. The new version offers improvements in force accuracy, in time-stepping, in adaptivity to a large dynamic range in timescales, in computational efficiency, and in parallel scalability through a special MPI/shared-memory parallelization and communication strategy, and a more-sophisticated domain decomposition algorithm. A manifestly momentum conserving fast multipole method (FMM) can be employed as an alternative to the one-sided TreePM gravity solver introduced in earlier versions. Two different flavours of smoothed particle hydrodynamics, a classic entropy-conserving formulation and a pressure-based approach, are supported for dealing with gaseous flows. The code is able to cope with very large problem sizes, thus allowing accurate predictions for cosmic structure formation in support of future precision tests of cosmology, and at the same time is well adapted to high dynamic range zoom-calculations with extreme variability of the particle number density in the simulated volume. The GADGET-4 code is publicly released to the community and contains infrastructure for on-the-fly group and substructure finding and tracking, as well as merger tree building, a simple model for radiative cooling and star formation, a high dynamic range power spectrum estimator, and an initial conditions generator based on second-order Lagrangian perturbation theory.

Axion scenarios in which the spontaneous breaking of the Peccei-Quinn symmetry takes place before or during inflation, and in which axion dark matter arises from the misalignment mechanism, can be constrained by Cosmic Microwave Background isocurvature bounds. Dark matter isocurvature is thought to be suppressed in models with axion-inflaton interactions, for which axion perturbations are assumed to freeze at horizon crossing during inflation. However, this assumption can be an oversimplification due to the interactions themselves. In particular, non-perturbative effects during reheating may lead to a dramatic growth of axion perturbations. We perform lattice calculations in two models in which the Peccei-Quinn field participates in inflation. We find that the growth of axion perturbations is such that the Peccei-Quinn symmetry is restored for an axion decay constant fA ≲ 1016–1017 GeV, leading to an over-abundance of dark matter, unless fA ≲ 2 × 1011 GeV. For fA ≳ 1016–1017 GeV we still find a large growth of axion perturbations at low momentum, such that a naive extrapolation to CMB scales suggests a violation of the isocurvature bounds.

A fraction of the dark matter in the solar neighborhood might be composed of non-galactic particles with speeds larger than the escape velocity of the Milky Way. The non-galactic dark matter flux would enhance the sensitivity of direct detection experiments, due to the larger momentum transfer to the target. In this note, we calculate the impact of the dark matter flux from the Local Group and the Virgo Supercluster diffuse components in nuclear and electron recoil experiments. The enhancement in the signal rate can be very significant, especially for experiments searching for dark matter induced electron recoils.

The emergence of evermore complex entities from prebiotic building blocks is a key aspect of origins of life research. The RNA-world hypothesis posits that RNA oligomers known as ribozymes acted as the first self-replicating entities. However, the mechanisms governing the self-assembly of complex informational polymers from the shortest prebiotic building blocks were unclear. One open issue concerns the relation between concentration and oligonucleotide length, usually assumed to be exponentially decreasing. Here, we show that a competition of timescales in the self-assembly of informational polymers by templated ligation generically leads to nonmonotonic strand-length distributions with two distinct length scales. The first length scale characterizes the onset of a strongly nonequilibrium regime and is visible as a local minimum. Dynamically, this regime is governed by extension cascades, where the elongation of a “primer” with a short building block is more likely than its dehybridization. The second length scale appears as a local concentration maximum and reflects a balance between degradation and dehybridization of completely hybridized double strands in a heterocatalytic extension-reassembly process. Analytical arguments and extensive numerical simulations within a sequence-independent model allowed us to predict and control these emergent length scales. Nonmonotonic strand-length distributions confirming our theory were obtained in thermocycler experiments using random DNA sequences from a binary alphabet. Our work emphasizes the role of structure-forming processes already for the earliest stages of prebiotic evolution. The accumulation of strands with a typical length reveals a possible starting point for higher-order self-organization events that ultimately lead to a self-replicating, evolving system.

We find the complete set of conditions satisfied by the forward 2 →2 scattering amplitude in unitary and causal theories. These are based on an infinite set of energy dependent quantities (the arcs) which are dispersively expressed as moments of a positive measure defined at (arbitrarily) higher energies. We identify optimal finite subsets of constraints, suitable to bound effective field theories (EFTs), at any finite order in the energy expansion. At tree level arcs are in a one to one correspondence with Wilson coefficients. We establish under which conditions this approximation applies, identifying seemingly viable EFTs where it never does. In all cases, we discuss the range of validity in both energy and couplings, where the latter has to satisfy two-sided bounds. We also extend our results to the case of small but finite t . A consequence of our study is that EFTs in which the scattering amplitude in some regime grows in energy faster than E⁶ cannot be UV completed.

The differential cross section for the quasi-free photoproduction reaction $\gamma n\rightarrow K^0\Sigma^0$ was measured at BGOOD at ELSA from threshold to a center-of-mass energy of 2400 MeV. An increase in the cross section is observed at forward angles above 2000 MeV. The available statistics prevent an accurate description of this behavior, however it appears consistent with models describing a resonance of dynamically generated vector meson-baryon states, where an equivalent model predicted the $P_C$ states observed at LHCb. If proven correct, this could indicate parallels between the strange and charmed quark sectors.

Using 324 numerically modelled galaxy clusters as provided by THE THREE HUNDRED project, we study the evolution of the kinematic properties of the stellar component of haloes on first infall. We selected objects with M_star > 5 × 10¹⁰ h⁻¹ M_⊙ within 3R₂₀₀ of the main cluster halo at z = 0 and followed their progenitors. We find that although haloes are stripped of their dark matter and gas after entering the main cluster halo, there is practically no change in their stellar kinematics. For the vast majority of our `galaxies' - defined as the central stellar component found within the haloes that form our sample - their kinematic properties, as described by the fraction of ordered rotation, and their position in the specific stellar angular momentum−stellar mass plane j_star − M_star are mostly unchanged by the influence of the central host cluster. However, for a small number of infalling galaxies, stellar mergers and encounters with remnant stellar cores close to the centre of the main cluster, particularly during pericentre passage, are able to spin up their stellar component by z = 0.

We investigate the impact of different assumptions in the modeling of one-loop galaxy bias on the recovery of cosmological parameters, as a follow-up of the analysis done in the first paper of the series at fixed cosmology. To carry out these tests we focus on the real-space galaxy-power spectrum from a set of three different synthetic galaxy samples whose clustering properties are meant to match the ones of the CMASS and LOWZ catalogs of BOSS and the SDSS Main Galaxy Sample. We investigate the relevance of allowing for either short range nonlocality or scale-dependent stochasticity by fitting the real-space galaxy autopower spectrum or the combination of galaxy-galaxy and galaxy-matter power spectrum. From a comparison among the goodness of fit (χ² ), unbiasedness of cosmological parameters (FoB), and figure of merit (FoM) of the model, we find that a simple four-parameter model (linear, quadratic, cubic nonlocal bias, and constant shot noise) with fixed quadratic tidal bias provides a robust modeling choice for the autopower spectrum of the three galaxy samples, up to k_max=0.3 h Mpc^-1 and for an effective volume of 6 h^-3 Gpc³. Instead, a joint analysis of the two observables fails at larger scales, and a model extension with either higher derivatives or scale-dependent shot noise is necessary to reach a similar k_max, with the latter providing the most accurate and stable results. Throughout the majority of the paper, we fix the description of the nonlinear matter evolution using a hybrid perturbative-N-body approach, RESPRESSO, that was found in the first paper to be the closest performing to the measured matter spectrum. We also test the impact of different modeling assumptions based on perturbative approaches, such as galilean-invariant Renormalised Perturbation Theory (gRPT) and effective field theory (EFT). In all cases, we find the inclusion of scale-dependent shot noise to increase the range of validity of the model in terms of FoB and χ². Interestingly, these model extensions with additional free parameters do not necessarily lead to an increase in the maximally achievable FoM for the cosmological parameters (h ,Ω_ch²,A_s), which are generally consistent with those of the simpler model at smaller k_max.

We study the transition widths of ϒ (10753 ) and ϒ (11020 ) into standard bottomonium under the hypothesis that they correspond to the two lowest laying 1^-- hybrid bottomonium states. We employ weakly coupled potential NRQCD an effective field theory incorporating the heavy-quark and multipole expansions. We consider the transitions generated by the leading order and next-to-leading order singlet-octet operators. In the multipole expansion the heavy-quark matrix elements factorize from the production of light-quark mesons by gluonic operators. For the leading order operator we compute the widths with a single π⁰, η or η^' in the final state and for the next-to-leading operator for π⁺π^- or K⁺K^-. The hadronization of the gluonic operators is obtained, in the first case, from the axial anomaly and a standard π⁰-η -η^' mixing scheme and, in the second case, we employ a coupled-channel dispersive representation matched to chiral perturbation theory for both the S - and D -wave pieces of the gluonic operator. We compare with experimental values and semi-inclusive widths. Our results strongly suggest that ϒ (11020 ) is indeed a hybrid bottomonium state.

Manual fits to spectral times series of Type Ia supernovae have provided a method of reconstructing the explosion from a parametric model but due to lack of information about model uncertainties or parameter degeneracies direct comparison between theory and observation is difficult. In order to mitigate this important problem we present a new way to probabilistically reconstruct the outer ejecta of the normal Type Ia supernova SN 2002bo. A single epoch spectrum, taken 10 days before maximum light, is fit by a 13-parameter model describing the elemental composition of the ejecta and the explosion physics (density, temperature, velocity, and explosion epoch). Model evaluation is performed through the application of a novel rapid spectral synthesis technique in which the radiative transfer code, TARDIS, is accelerated by a machine-learning framework. Analysis of the posterior distribution reveals a complex and degenerate parameter space and allows direct comparison to various hydrodynamic models. Our analysis favors detonation over deflagration scenarios and we find that our technique offers a novel way to compare simulation to observation.

The SuperKEKB accelerator in Tsukuba, Japan is providing e$^+$e$^-$ beams for the Belle II experiment since March 2019. To deal with the aimed peak luminosity being forty times higher than the one recorded at Belle, a pixel detector based on DEPFET technology has been installed. It features a long integration time of 20 $\mu$s resulting in an expected data rate of 20 GByte/s (160 GBit/s) at a maximum occupancy of 3 %. To deal with this high amount of data, the data handling hub (DHH) has been developed. It contains all necessary functionality for the control and readout of the detector. In this paper we describe the architecture and features of the DHH system. Further we will show the key performance characteristics after one year of operation.

A free-floating planet is a planetary-mass object that orbits around a non-stellar massive object (e.g. a brown dwarf) or around the Galactic Center. The presence of exomoons orbiting free-floating planets has been theoretically predicted by several models. Under specific conditions, these moons are able to retain an atmosphere capable of ensuring the long-term thermal stability of liquid water on their surface. We model this environment with a one-dimensional radiative-convective code coupled to a gas-phase chemical network including cosmic rays and ion-neutral reactions. We find that, under specific conditions and assuming stable orbital parameters over time, liquid water can be formed on the surface of the exomoon. The final amount of water for an Earth-mass exomonoon is smaller than the amount of water in Earth oceans, but enough to host the potential development of primordial life. The chemical equilibrium time-scale is controlled by cosmic rays, the main ionization driver in our model of the exomoon atmosphere.

We present an empirical model for the number of globular clusters (GCs) in galaxies based on recent data showing a tight relationship between dark matter halo virial masses and GC numbers. While a simple base model forming GCs in low-mass haloes reproduces this relation, we show that a second formation pathway for GCs is needed to account for observed younger GC populations. We confirm previous works that reported the observed linear correlation as being a consequence of hierarchical merging and its insensitivity to the exact GC formation processes at higher virial masses, even for a dual formation scenario. We find that the scatter of the linear relation is strongly correlated with the relative amount of smooth accretion: the more dark matter is smoothly accreted, the fewer GCs a halo has compared to other haloes of the same mass. This scatter is smaller than that introduced by halo mass measurements, indicating that the number of GCs in a galaxy is a good tracer for its dark matter mass. Smooth accretion is also the reason for a lower average dark matter mass per GC in low-mass haloes. Finally, we successfully reproduce the observed general trend of GCs being old and the tendency of more massive haloes hosting older GC systems. Including the second GC formation mechanism through gas-rich mergers leads to a more realistic variety of GC age distributions and also introduces an age inversion in the halo virial mass range log M_vir/M_⊙ = 11-13.

We present a set of nonlocal thermodynamic equilibrium steady-state calculations of radiative transfer for one-year-old Type II supernovae (SNe) starting from state-of-the-art explosion models computed with detailed nucleosynthesis. This grid covers single-star progenitors with initial masses between 9 and 29 M_⊙, all evolved with the code KEPLER at solar metallicity and ignoring rotation. The [O I] λλ 6300, 6364 line flux generally grows with progenitor mass, and Hα exhibits an equally strong and opposite trend. The [Ca II] λλ 7291, 7323 strength increases at low ⁵⁶Ni mass, at low explosion energy, or with clumping. This Ca II doublet, which forms primarily in the explosively produced Si/S zones, depends little on the progenitor mass but may strengthen if Ca⁺ dominates in the H-rich emitting zones or if Ca is abundant in the O-rich zones. Indeed, Si-O shell merging prior to core collapse may boost the Ca II doublet at the expense of the O I doublet, and may thus mimic the metal line strengths of a lower-mass progenitor. We find that the ⁵⁶Ni bubble effect has a weak impact, probably because it is too weak to induce much of an ionization shift in the various emitting zones. Our simulations compare favorably to observed SNe II, including SN 2008bk (e.g., the 9 M_⊙ model), SN 2012aw (12 M_⊙ model), SN 1987A (15 M_⊙ model), or SN 2015bs (25 M_⊙ model with no Si-O shell merging). SNe II with narrow lines and a low ⁵⁶Ni mass are well matched by the weak explosion of 9-11 M_⊙ progenitors. The nebular-phase spectra of standard SNe II can be explained with progenitors in the mass range 12-15 M_⊙, with one notable exception for SN 2015bs. In the intermediate mass range, these mass estimates may increase by a few M_⊙, with allowance for clumping of the O-rich material or CO molecular cooling.

The temperatures of red supergiants (RSGs) are expected to depend on metallicity (Z) in such a way that lower Z RSGs are warmer. In this work, we investigate the Z-dependence of the Hayashi limit by analysing RSGs in the low-Z galaxy Wolf-Lundmark-Mellote, and compare with the RSGs in the higher Z environments of the Small Magellanic Cloud and Large Magellanic Cloud. We determine the effective temperature (T_eff) of each star by fitting their spectral energy distributions, as observed by VLT + SHOOTER, with MARCS model atmospheres. We find average temperatures of $T_{\textrm {eff}_{\textrm {WLM}}}=4400\pm 202$ K, $T_{\textrm {eff}_{\textrm {SMC}}}=4130\pm 103$ K, and $T_{\textrm {eff}_{\textrm {LMC}}}=4140\pm 148$ K. From population synthesis analysis, we find that although the Geneva evolutionary models reproduce this trend qualitatively, the RSGs in these models are systematically too cool. We speculate that our results can be explained by the inapplicability of the standard solar mixing length to RSGs.

Within the transport model evaluation project (TMEP) of simulations for heavy-ion collisions, the mean-field response is examined here. Specifically, zero-sound propagation is considered for neutron-proton symmetric matter enclosed in a periodic box, at zero temperature and around normal density. The results of several transport codes belonging to two families (BUU-like and QMD-like) are compared among each other and to exact calculations. For BUU-like codes, employing the test particle method, the results depend on the combination of the number of test particles and the spread of the profile functions that weight integration over space. These parameters can be properly adapted to give a good reproduction of the analytical zero-sound features. QMD-like codes, using molecular dynamics methods, are characterized by large damping effects, attributable to the fluctuations inherent in their phase-space representation. Moreover, for a given nuclear effective interaction, they generally lead to slower density oscillations, as compared to BUU-like codes. The latter problem is mitigated in the more recent lattice formulation of some of the QMD codes. The significance of these results for the description of real heavy-ion collisions is discussed.

We present Large Millimeter Telescope (LMT)/AzTEC 1.1 mm observations of ~100 luminous high-redshift dusty star-forming galaxy candidates from the $\sim 600\,$ sq.deg Herschel-ATLAS survey, selected on the basis of their SPIRE red far-infrared colours and with $S_{500\, \mu \rm m}=35-80$ mJy. With an effective $\theta _{\rm FWHM}\approx 9.5\,$arcsec angular resolution, our observations reveal that at least 9 per cent of the targets break into multiple systems with signal-to-noise ratio ≥4 members. The fraction of multiple systems increases to ~23 per cent (or more) if some non-detected targets are considered multiples, as suggested by the data. Combining the new AzTEC and deblended Herschel photometry, we derive photometric redshifts, infrared luminosities, and star formation rates. While the median redshifts of the multiple and single systems are similar (z_med ≍ 3.6), the redshift distribution of the latter is skewed towards higher redshifts. Of the AzTEC sources, ~85 per cent lie at z_phot > 3 while ~33 per cent are at z_phot > 4. This corresponds to a lower limit on the space density of ultrared sources at 4 < z < 6 of $\sim 3\times 10^{-7}\, \textrm {Mpc}^{-3}$ with a contribution to the obscured star formation of $\gtrsim 8\times 10^{-4}\, \textrm {M}_\odot \, \textrm {yr}^{-1} \, \textrm {Mpc}^{-3}$. Some of the multiple systems have members with photometric redshifts consistent among them suggesting possible physical associations. Given their angular separations, these systems are most likely galaxy over-densities and/or early-stage pre-coalescence mergers. Finally, we present 3 mm LMT/RSR spectroscopic redshifts of six red-Herschel galaxies at z_spec = 3.85-6.03, two of them (at z ~ 4.7) representing new redshift confirmations. Here, we release the AzTEC and deblended Herschel photometry as well as catalogues of the most promising interacting systems and z > 4 galaxies.

A search for charginos and neutralinos at the Large Hadron Collider using fully hadronic final states and missing transverse momentum is reported. Pair-produced charginos or neutralinos are explored, each decaying into a high-<math display="inline"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> Standard Model weak boson. Fully hadronic final states are studied to exploit the advantage of the large branching ratio, and the efficient rejection of backgrounds by identifying the high-<math display="inline"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> bosons using large-radius jets and jet substructure information. An integrated luminosity of <math display="inline"><mrow><mn>139</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></math> of proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 13 TeV is used. No significant excess is found beyond the Standard Model expectation. Exclusion limits at the 95% confidence level are set on wino or higgsino production with various assumptions about the decay branching ratios and the type of lightest supersymmetric particle. A wino (higgsino) mass up to 1060 (900) GeV is excluded when the lightest supersymmetry particle mass is below 400 (240) GeV and the mass splitting is larger than 400 (450) GeV. The sensitivity to high-mass winos and higgsinos is significantly extended relative to previous LHC searches using other final states.

In this paper we investigate the potential of current and upcoming cosmological surveys to constrain the mass and abundance of ultra-light axion (ULA) cosmologies with galaxy cluster number counts. ULAs, sometimes also referred to as Fuzzy Dark Matter, are well-motivated in many theories beyond the Standard Model and could potentially solve the ΛCDM small-scale crisis. Galaxy cluster counts provide a robust probe of the formation of structures in the Universe. Their distribution in mass and redshift is strongly sensitive to the underlying linear matter perturbations. In this forecast paper we explore two scenarios, firstly an exclusion limit on axion mass given a no-axion model and secondly constraints on an axion model. With this we obtain lower limits on the ULA mass on the order of m_a ≳ 10^-24 eV. However, this result depends heavily on the mass of the smallest reliably observable clusters for a given survey. Cluster counts, like many other cosmological probes, display an approximate degeneracy in the ULA mass vs. abundance parameter space, which is dependent on the characteristics of the probe. These degeneracies are different for other cosmological probes. Hence galaxy cluster counts might provide a complementary window on the properties of ultra-light axions.

We present non-radiative, cosmological zoom-in simulations of galaxy-cluster formation with magnetic fields and (anisotropic) thermal conduction of one massive galaxy cluster with M

$_{vir}$ ∼ 2 × 10$^{15}$

M

$_{⊙}$ at z ∼ 0. We run the cluster on three resolution levels (1×, 10×, 25×), starting with an effective mass resolution of 2 × 10$^{8}$

M

$_{⊙}$, subsequently increasing the particle number to reach 4 × 10$^{6}$

M

$_{⊙}$. The maximum spatial resolution obtained in the simulations is limited by the gravitational softening reaching ϵ = 1.0 kpc at the highest resolution level, allowing one to resolve the hierarchical assembly of the structures in fine detail. All simulations presented are carried out with the SPMHD code gadget3 with an updated SPMHD prescription. The primary focus of this paper is to investigate magnetic field amplification in the intracluster medium. We show that the main amplification mechanism is the small-scale turbulent dynamo in the limit of reconnection diffusion. In our two highest resolution models we start to resolve the magnetic field amplification driven by the dynamo and we explicitly quantify this with the magnetic power spectra and the curvature of the magnetic field lines, consistent with dynamo theory. Furthermore, we investigate the ∇ ·

B

= 0 constraint within our simulations and show that we achieve comparable results to state-of-the-art AMR or moving-mesh techniques, used in codes such as enzo and arepo. Our results show for the first time in a cosmological simulation of a galaxy cluster that dynamo action can be resolved with modern numerical Lagrangian magnetohydrodynamic methods, a study that is currently missing in the literature.

Time-delay cosmography with gravitationally lensed quasars plays an important role in anchoring the absolute distance scale and hence measuring the Hubble constant, H₀, independent of traditional distance ladder methodology. A current potential limitation of time-delay distance measurements is the mass-sheet transformation (MST), which leaves the lensed imaging unchanged but changes the distance measurements and the derived value of H₀. In this work we show that the standard method of addressing the MST in time-delay cosmography, through a combination of high-resolution imaging and the measurement of the stellar velocity dispersion of the lensing galaxy, depends on the assumption that the ratio, D_s/D_ds, of angular diameter distances to the background quasar and between the lensing galaxy and the quasar can be constrained. This is typically achieved through the assumption of a particular cosmological model. Previous work (TDCOSMO IV) addressed the mass-sheet degeneracy and derived H₀ under the assumption of the ΛCDM model. In this paper we show that the mass-sheet degeneracy can be broken without relying on a specific cosmological model by combining lensing with relative distance indicators such as supernovae Type Ia and baryon acoustic oscillations, which constrain the shape of the expansion history and hence D_s/D_ds. With this approach, we demonstrate that the mass-sheet degeneracy can be constrained in a cosmological model-independent way. Hence model-independent distance measurements in time-delay cosmography under MSTs can be obtained.

Catalytic nucleic acids, such as ribozymes, are central to a variety of origin-of-life scenarios. Typically, they require elevated magnesium concentrations for folding and activity, but their function can be inhibited by high concentrations of monovalent salts. Here we show that geologically plausible high-sodium, low-magnesium solutions derived from leaching basalt (rock and remelted glass) inhibit ribozyme catalysis, but that this activity can be rescued by selective magnesium up-concentration by heat flow across rock fissures. In contrast to up-concentration by dehydration or freezing, this system is so far from equilibrium that it can actively alter the Mg:Na salt ratio to an extent that enables key ribozyme activities, such as self-replication and RNA extension, in otherwise challenging solution conditions. The principle demonstrated here is applicable to a broad range of salt concentrations and compositions, and, as such, highly relevant to various origin-of-life scenarios.

We use hydrodynamical separate universe simulations with the IllustrisTNG model to predict the local primordial non-Gaussianity (PNG) bias parameters b

$_{ϕ}$ and b

$_{ϕδ}$, which enter at leading order in the galaxy power spectrum and bispectrum. This is the first time that b

$_{ϕδ}$ is measured from either gravity-only or galaxy formation simulations. For dark matter halos, the popular assumption of universality overpredicts the b

$_{ϕδ}$(b

$_{1}$) relation in the range 1 ≲ b

$_{1}$ ≲ 3 by up to Δ b

$_{ϕδ}$ ∼ 3 (b

$_{1}$ is the linear density bias). The adequacy of the universality relation is worse for the simulated galaxies, with the relations b

$_{ϕ}$(b

$_{1}$) and b

$_{ϕδ}$(b

$_{1}$) being generically redshift-dependent and very sensitive to how galaxies are selected (we test total, stellar and black hole mass, black hole mass accretion rate and color). The uncertainties on b

$_{ϕ}$ and b

$_{ϕδ}$ have a direct, often overlooked impact on the constraints of the local PNG parameter f

$_{NL}$, which we study and discuss. For a survey with V = 100 Gpc$^{3}$/h$^{3}$ at z=1, uncertainties Δ b

$_{ϕ}$ ≲ 1 and Δ b

$_{ϕδ}$ ≲ 5 around values close to the fiducial can yield relatively unbiased constraints on f

$_{NL}$ using power spectrum and bispectrum data. We also show why priors on galaxy bias are useful even in analyses that fit for products f

$_{NL}$

b

$_{ϕ}$ and f

$_{NL}$

b

$_{ϕδ}$. The strategies we discuss to deal with galaxy bias uncertainties can be straightforwardly implemented in existing f

$_{NL}$ constraint analyses (we provide fits for some of the bias relations). Our results motivate more works with galaxy formation simulations to refine our understanding of b

$_{ϕ}$ and b

$_{ϕδ}$ towards improved constraints on f

$_{NL}$.

The properties of quasar-host galaxies might be determined by the growth and feedback of their supermassive black holes (SMBHs, 10^8−10 M_⊙). We investigate such connection with a suite of cosmological simulations of massive (halo mass ≈10^12 M_⊙) galaxies at z ≃ 6 that include a detailed subgrid multiphase gas and accretion model. BH seeds of initial mass 10^5 M_⊙ grow mostly by gas accretion, and become SMBH by z = 6 setting on the observed M_BH−M_⋆ relation without the need for a boost factor. Although quasar feedback crucially controls the SMBH growth, its impact on the properties of the host galaxy at z = 6 is negligible. In our model, quasar activity can both quench (via gas heating) or enhance (by interstellar medium overpressurization) star formation. However, we find that the star formation history is insensitive to such modulation as it is largely dominated, at least at z > 6, by cold gas accretion from the environment that cannot be hindered by the quasar energy deposition. Although quasar-driven outflows can achieve velocities |$\gt 1000~\rm km~s^{-1}$|⁠, only ≈4 per cent of the outflowing gas mass can actually escape from the host galaxy. These findings are only loosely constrained by available data, but can guide observational campaigns searching for signatures of quasar feedback in early galaxies.

The emergence of evermore complex entities from prebiotic building blocks is a key aspect of origins of life research. The RNA-world hypothesis posits that RNA oligomers known as ribozymes acted as the first self-replicating entities. However, the mechanisms governing the self-assembly of complex informational polymers from the shortest prebiotic building blocks were unclear. One open issue concerns the relation between concentration and oligonucleotide length, usually assumed to be exponentially decreasing. Here, we show that a competition of timescales in the self-assembly of informational polymers by templated ligation generically leads to nonmonotonic strand-length distributions with two distinct length scales. The first length scale characterizes the onset of a strongly nonequilibrium regime and is visible as a local minimum. Dynamically, this regime is governed by extension cascades, where the elongation of a "primer" with a short building block is more likely than its dehybridization. The second length scale appears as a local concentration maximum and reflects a balance between degradation and dehybridization of completely hybridized double strands in a heterocatalytic extension-reassembly process. Analytical arguments and extensive numerical simulations within a sequence-independent model allowed us to predict and control these emergent length scales. Nonmonotonic strand-length distributions confirming our theory were obtained in thermocycler experiments using random DNA sequences from a binary alphabet. Our work emphasizes the role of structure-forming processes already for the earliest stages of prebiotic evolution. The accumulation of strands with a typical length reveals a possible starting point for higher-order self-organization events that ultimately lead to a self-replicating, evolving system.

Simulating a survey of fluxes and redshifts (distances) from an astrophysical population is a routine task. \texttt{popsynth} provides a generic, object-oriented framework to produce synthetic surveys from various distributions and luminosity functions, apply selection functions to the observed variables and store them in a portable (HDF5) format. Population synthesis routines can be constructed either using classes or from a serializable YAML format allowing flexibility and portability. Users can not only sample the luminosity and distance of the populations, but they can create auxiliary distributions for parameters which can have arbitrarily complex dependencies on one another. Thus, users can simulate complex astrophysical populations which can be used to calibrate analysis frameworks or quickly test ideas.

Molecular outflows contributing to the matter cycle of star-forming galaxies are now observed in small and large systems at low and high redshift. Their physical origin is still unclear. In most theoretical studies, only warm ionized/neutral and hot gas outflowing from the interstellar medium is generated by star formation. We investigate an in situ H₂ formation scenario in the outflow using high-resolution simulations, including non-equilibrium chemistry and self-gravity, of turbulent, warm, and atomic clouds with densities 0.1, 0.5, and $1\, \mathrm{cm}^{-3}$ exposed to a magnetized hot wind. For cloud densities $\gtrsim 0.5\, \mathrm{cm}^{-3}$, a magnetized wind triggers H₂ formation before cloud dispersal. Up to 3 per cent of the initial cloud mass can become molecular on $\sim \! 10\, \mathrm{Myr}$ time-scales. The effect is stronger for winds with perpendicular B-fields and intermediate density clouds ($n_\mathrm{c}\sim 0.5\, \mathrm{cm}^{-3}$). Here, H₂ formation can be boosted by up to one order of magnitude compared to isolated cooling clouds independent of self-gravity. Self-gravity preserves the densest clouds well past their $\sim \! 15\, \mathrm{Myr}$ cloud crushing time-scales. This model could provide a plausible in situ origin for the observed molecular gas. All simulations form warm ionized gas, which represents an important observable phase. The amount of warm ionized gas is almost independent of the cloud density but solely depends on the magnetic field configuration in the wind. For low-density clouds ($0.1\, \mathrm{cm}^{-3}$), up to 60 per cent of the initially atomic cloud mass can become warm and ionized.

Hydroxyl ($\rm OH$) is known to form efficiently in cold gas (T ~ 100 K) along with the molecule $\rm H_2$ and can be used as an efficient tracer of the diffuse molecular gas in the interstellar medium (ISM). Using a simple formalism describing the $\rm H\, I/H_2$ transition and a reduced network of major chemical reactions, we present a semi-analytical prescription to estimate the abundances of O-bearing molecules in the diffuse ISM. We show that predictions based on our prescription are in good agreement with the estimates obtained using the MEUDON PDR code which utilizes the full reaction network. We investigate the dependence of the relative abundances of $\rm OH/H\, I$ and $\rm OH/H_2$ on the variations of physical conditions i.e. the metallicity, number density (n), cosmic ray ionization rate (ζ), and strength of UV field (χ) in the medium. We find that the $\rm OH/H\, I$ abundances observed in the Galactic ISM can be reproduced by models with n ~ 50 cm^-3, χ ~ 1 (Mathis field), and ζ ~ 3 × 10^-17 s^-1, with a variation of about 1 dex allowed around these values. Using the constrained $\rm H_2$ column density distribution function at z ~ 3, we estimate the $\rm OH$ column density distribution function and discuss future prospects with the upcoming large radio absorption line surveys.

The structure of protostellar cores can often be approximated by isothermal Bonnor-Ebert spheres (BES), which are stabilized by an external pressure. For the typical pressure of 10⁴k_B K cm^-3 to 10⁵k_B K cm^-3 found in molecular clouds, cores with masses below 1.5 M_⊙ are stable against gravitational collapse. In this paper, we analyze the efficiency of triggering gravitational collapse with a nearby stellar wind, which represents an interesting scenario for triggering low-mass star formation. We analytically derive a new stability criterion for a BES compressed by a stellar wind, which depends on its initial nondimensional radius ${\xi }_{\max }$ . If the stability limit is violated the wind triggers a core collapse. Otherwise, the core is destroyed by the wind. We estimate its validity range to $2.5\lt {\xi }_{\max }\lt 4.2$ and confirm this in simulations with the SPH-Code GADGET-3. The efficiency of triggering a gravitational collapse strongly decreases for ${\xi }_{\max }\lt 2.5$ since in this case destruction and acceleration of the whole sphere begin to dominate. We were unable to trigger a collapse for ${\xi }_{\max }\lt 2$ , which leads to the conclusion that a stellar wind can move the smallest unstable stellar mass to 0.5 M_⊙ and that destabilizing even smaller cores would require external pressure larger than 10⁵k_B K cm^-3. For ${\xi }_{\max }\gt 4.2$ the expected wind strength according to our criterion is small enough that the compression is slower than the sound speed of the BES and sound waves can be triggered. In this case our criterion somewhat underestimates the onset of collapse and detailed numerical analyses are required.

Orbit superposition models are a non-parametric dynamical modelling technique to determine the mass of a galaxy's central supermassive black hole (SMBH), its stars, or its dark matter halo. One of the main problems is how to decide which model out of a large pool of trial models based on different assumed mass distributions represents the true structure of an observed galaxy best. We show that the traditional approach to judge models solely by their goodness-of-fit can lead to substantial biases in estimated galaxy properties caused by varying model flexibilities. We demonstrate how the flexibility of the models can be estimated using bootstrap iterations and present a model selection framework that removes these biases by taking the variable flexibility into account in the model evaluation. We extend the model selection approach to optimize the degree of regularization directly from the data. Altogether, this leads to a significant improvement of the constraining power of the modelling technique. We show with simulations that one can reconstruct the mass, anisotropy, and viewing angle of an axisymmetric galaxy with a few per cent accuracy from realistic observational data with fully resolved line-of-sight velocity distributions (LOSVDs). In a first application, we reproduce a photometric estimate of the inclination of the disc galaxy NGC 3368 to within 5° accuracy from kinematic data that cover only a few sphere-of-influence radii around the galaxy's SMBH. This demonstrates the constraining power that can be achieved with orbit models based on fully resolved LOSVDs and a model selection framework.

We present an overview of the Middle Ages Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey, a Large Program on the European Southern Observatory Very Large Telescope. MAGPI is designed to study the physical drivers of galaxy transformation at a lookback time of 3-4 Gyr, during which the dynamical, morphological, and chemical properties of galaxies are predicted to evolve significantly. The survey uses new medium-deep adaptive optics aided Multi-Unit Spectroscopic Explorer (MUSE) observations of fields selected from the Galaxy and Mass Assembly (GAMA) survey, providing a wealth of publicly available ancillary multi-wavelength data. With these data, MAGPI will map the kinematic and chemical properties of stars and ionised gas for a sample of 60 massive ( ${>}7 × 10^{10} {M}_\odot$ ) central galaxies at $0.25 < z <0.35$ in a representative range of environments (isolated, groups and clusters). The spatial resolution delivered by MUSE with Ground Layer Adaptive Optics ( $0.6-0.8$ arcsec FWHM) will facilitate a direct comparison with Integral Field Spectroscopy surveys of the nearby Universe, such as SAMI and MaNGA, and at higher redshifts using adaptive optics, for example, SINS. In addition to the primary (central) galaxy sample, MAGPI will deliver resolved and unresolved spectra for as many as 150 satellite galaxies at $0.25 < z <0.35$ , as well as hundreds of emission-line sources at $z < 6$ . This paper outlines the science goals, survey design, and observing strategy of MAGPI. We also present a first look at the MAGPI data, and the theoretical framework to which MAGPI data will be compared using the current generation of cosmological hydrodynamical simulations including EAGLE, Magneticum, HORIZON-AGN, and Illustris-TNG. Our results show that cosmological hydrodynamical simulations make discrepant predictions in the spatially resolved properties of galaxies at $z≈ 0.3$ . MAGPI observations will place new constraints and allow for tangible improvements in galaxy formation theory.

Our work presents an independent calibration of the J-region Asymptotic Giant Branch (JAGB) method using Infrared Survey Facility photometric data and a custom luminosity function profile to determine JAGB mean magnitudes for nine galaxies. We determine a mean absolute magnitude of carbon stars of M_LMC = -6.212 ± 0.010 (stat.) ±0.030 (syst.) mag. We then use near-infrared photometry of a number of nearby galaxies, originally obtained by our group to determine their distances from Cepheids using the Leavitt law, in order to independently determine their distances with the JAGB method. We compare the JAGB distances obtained in this work with the Cepheid distances resulting from the same photometry and find very good agreement between the results from the two methods. The mean difference is 0.01 mag with an rms scatter of 0.06 mag after taking into account seven out of the eight analyzed galaxies that had their distances determined using Cepheids. The very accurate distance to the Small Magellanic Cloud based on detached eclipsing binaries is also in very good agreement with the distance obtained from carbon stars.

Self-interacting dark matter (SIDM) models have the potential to solve the small-scale problems that arise in the cold dark matter paradigm. Simulations are a powerful tool for studying SIDM in the context of astrophysics, but it is numerically challenging to study differential cross-sections that favour small-angle scattering (as in light-mediator models). Here, we present a novel approach to model frequent scattering based on an effective drag force, which we have implemented into the N-body code GADGET-3. In a range of test problems, we demonstrate that our implementation accurately models frequent scattering. Our implementation can be used to study differences between SIDM models that predict rare and frequent scattering. We simulate core formation in isolated dark matter haloes, as well as major mergers of galaxy clusters and find that SIDM models with rare and frequent interactions make different predictions. In particular, frequent interactions are able to produce larger offsets between the distribution of galaxies and dark matter in equal-mass mergers.

We propose the construction of LEGEND-1000, the ton-scale Large Enriched Germanium Experiment for Neutrinoless $\beta \beta$ Decay. This international experiment is designed to answer one of the highest priority questions in fundamental physics. It consists of 1000 kg of Ge detectors enriched to more than 90% in the $^{76}$Ge isotope operated in a liquid argon active shield at a deep underground laboratory. By combining the lowest background levels with the best energy resolution in the field, LEGEND-1000 will perform a quasi-background-free search and can make an unambiguous discovery of neutrinoless double-beta decay with just a handful of counts at the decay $Q$ value. The experiment is designed to probe this decay with a 99.7%-CL discovery sensitivity in the $^{76}$Ge half-life of $1.3\times10^{28}$ years, corresponding to an effective Majorana mass upper limit in the range of 9-21 meV, to cover the inverted-ordering neutrino mass scale with 10 yr of live time.

We present a method to derive conservative upper limits on the coupling constants of the effective theory of dark matter-nucleon interactions, taking into account the interference among operators. The method can be applied in any basis, and can be easily particularized to any UV complete model. To illustrate our method, we use the IceCube constraints on an exotic neutrino flux from dark matter annihilations in the Sun to derive conservative upper limits on the dark matter-nucleon coupling constants of the effective theory, as well as to derive conservative upper limits on the dark matter-proton and dark matter-neutron scattering cross-sections.

In the last decade, quantum simulators, and in particular cold atoms in optical lattices, have emerged as a valuable tool to study strongly correlated quantum matter. These experiments are now reaching regimes that are numerically difficult or impossible to access. In particular they have started to fulfill a promise which has contributed significantly to defining and shaping the field of cold atom quantum simulations, namely the exploration of doped and frustrated quantum magnets and the search for the origins of high-temperature superconductivity in the fermionic Hubbard model. Despite many future challenges lying ahead, such as the need to further lower the experimentally accessible temperatures, remarkable studies have already been conducted. Among them, spin-charge separation in one-dimensional systems has been demonstrated, extended-range antiferromagnetism in two-dimensional systems has been observed, connections to modern day large-scale numerical simulations were made, and unprecedented comparisons with microscopic trial wavefunctions have been carried out at finite doping. In many regards, the field has acquired new realms, putting old ideas to a new test and producing new insights and inspiration for the next generation of physicists. In the first part of this paper, we review the results achieved in cold atom realizations of the Fermi–Hubbard model in recent years. We put special emphasis on the new probes available in quantum gas microscopes, such as higher-order correlation functions, full counting statistics, the ability to study far-from-equilibrium dynamics, machine learning and pattern recognition of instantaneous snapshots of the many-body wavefunction, and access to non-local correlators. Our review is written from a theoretical perspective, but aims to provide basic understanding of the experimental procedures. We cover one-dimensional systems, where the phenomenon of spin-charge separation is ubiquitous, and two-dimensional systems where we distinguish between situations with and without doping. Throughout, we focus on the strong coupling regime where the Hubbard interactions <math display="inline" id="d1e3228" altimg="si1.svg"><mi>U</mi></math> dominate and connections to <math display="inline" id="d1e3233" altimg="si421.svg"><mrow><mi>t</mi><mo linebreak="goodbreak" linebreakstyle="after">−</mo><mi>J</mi></mrow></math> models can be justified. In the second part of this paper, with the stage set and the current state of the field in mind, we propose a new direction for cold atoms to explore: namely mixed-dimensional bilayer systems, where the charge motion is restricted to individual layers which remain coupled through spin-exchange. These systems can be directly realized experimentally and we argue that they have a rich phase diagram, potentially including a strongly correlated BEC-to-BCS cross-over and regimes with different superconducting order parameters, as well as complex parton phases and possibly even analogs of tetraquark states. In particular, we propose a novel, strong pairing mechanism in these systems, which puts the formation of hole pairs at experimentally accessible, elevated temperatures within reach. Ultimately we propose to explore how the physics of the mixed-dimensional bilayer system can be connected to the rich phenomenology of the single-layer Hubbard model. •Comprehensive review of cold atom experiments on the Fermi–Hubbard model.•Focus on physics highlights, from a theoretical perspective.•New results for hole-pairing in bilayer and ladder systems.•Including a discussion of contemporary analysis tools: from machine-learning to ARPES.

We present a model for the halo-mass correlation function that explicitly incorporates halo exclusion and allows for a redefinition of the halo boundary in a flexible way. We assume that haloes trace mass in a way that can be described using a single scale-independent bias parameter. However, our model exhibits scale-dependent biasing due to the impact of halo-exclusion, the use of a 'soft' (i.e. not infinitely sharp) halo boundary, and differences in the one halo term contributions to ξ_hm and ξ_mm. These features naturally lead us to a redefinition of the halo boundary that lies at the 'by eye' transition radius from the one-halo to the two-halo term in the halo-mass correlation function. When adopting our proposed definition, our model succeeds in describing the halo-mass correlation function with $\approx 2{{\ \rm per\ cent}}$ residuals over the radial range 0.1 h^-1 Mpc < r < 80 h^-1 Mpc, and for halo masses in the range 10¹³ h^-1 M_⊙ < M < 10¹⁵ h^-1 M_⊙. Our proposed halo boundary is related to the splashback radius by a roughly constant multiplicative factor. Taking the 87 percentile as reference we find r_t/R_sp ≍ 1.3. Surprisingly, our proposed definition results in halo abundances that are well described by the Press-Schechter mass function with δ_sc = 1.449 ± 0.004. The clustering bias parameter is offset from the standard background-split prediction by $\approx 10{{\ \rm per\ cent}}\!-\!15{{\ \rm per\ cent}}$. This level of agreement is comparable to that achieved with more standard halo definitions.

We study the gravitational radiation emitted during the scattering of two spinless bodies in the post-Minkowskian effective field theory approach. We derive the conserved stress-energy tensor linearly coupled to gravity and the classical probability amplitude of graviton emission at leading and next-to-leading order in the Newton's constant G . The amplitude can be expressed in compact form as one-dimensional integrals over a Feynman parameter involving Bessel functions. We use it to recover the leading-order radiated angular momentum expression. Upon expanding it in the relative velocity between the two bodies v , we compute the total four-momentum radiated into gravitational waves at leading-order in G and up to an order v^{, 8} finding agreement with what was recently computed using scattering amplitude methods. Our results also allow us to investigate the zero frequency limit of the emitted energy spectrum.

We revisit light-cone sum rules with pion distribution amplitudes to determine the full set of local B→π form factors. To this end, we determine all duality threshold parameters from a Bayesian fit for the first time. Our results, obtained at small momentum transfer q2, are extrapolated to large q2 where they agree with precise lattice QCD results. We find that a modification to the commonly used BCL parametrization is crucial to interpolate the scalar form factor between the two q2 regions. We provide numerical results for the form factor parameters -- including their covariance -- based on simultaneous fit of all three form factors to both the sum rule and lattice QCD results. Our predictions for the form factors agree well with measurements of the q2 spectrum of the semileptonic decay B¯0→π+ℓ−ν¯. From the world average of the latter we obtain |Vub|=(3.77±0.15)⋅10−3, which is in agreement with the most recent inclusive determination at the 1σ level.

The evolution of young stars and disks is driven by the interplay of several processes, notably the accretion and ejection of material. These processes, critical to correctly describe the conditions of planet formation, are best probed spectroscopically. Between 2020 and 2022, about 500orbits of the Hubble Space Telescope (HST) are being devoted in to the ULLYSES public survey of about 70 low-mass (M_⋆ ≤ 2 M_⊙) young (age < 10 Myr) stars at UV wavelengths. Here, we present the PENELLOPE Large Program carried out with the ESO Very Large Telescope (VLT) with the aim of acquiring, contemporaneously to the HST, optical ESPRESSO/UVES high-resolution spectra for the purpose of investigating the kinematics of the emitting gas, along with UV-to-NIR X-shooter medium-resolution flux-calibrated spectra to provide the fundamental parameters that HST data alone cannot provide, such as extinction and stellar properties. The data obtained by PENELLOPE have no proprietary time and the fully reduced spectra are being made available to the whole community. Here, we describe the data and the first scientific analysis of the accretion properties for the sample of 13 targets located in the Orion OB1 association and in the σ-Orionis cluster, observed in November-December 2020. We find that the accretion rates are in line with those observed previously in similarly young star-forming regions, with a variability on a timescale of days (≲3). The comparison of the fits to the continuum excess emission obtained with a slab model on the X-shooter spectra and the HST/STIS spectra shows a shortcoming in the X-shooter estimates of ≲10%, which is well within the assumed uncertainty. Its origin can be either due to an erroneous UV extinction curve or to the simplicity of the modeling and, thus, this question will form the basis of the investigation undertaken over the course of the PENELLOPE program. The combined ULLYSES and PENELLOPE data will be key in attaining a better understanding of the accretion and ejection mechanisms in young stars.

Based on observations collected at the European Southern Observatory under ESO programme 106.20Z8.

We use the forward modeling approach to galaxy clustering combined with the likelihood from the effective-field theory of large-scale structure to measure assembly bias, i.e. the dependence of halo bias on properties beyond the total mass, in the linear (b1) and second order bias parameters (b2 and bK2) of dark matter halos in N-body simulations. This is the first time that assembly bias in the tidal bias parameter bK2 is measured. We focus on three standard halo properties: the concentration c, spin λ, and sphericity s, for which we find an assembly bias signal in bK2 that is opposite to that in b1. Specifically, at fixed mass, halos that get more (less) positively biased in b1, get less (more) negatively biased in bK2. We also investigate the impact of assembly bias on the b2(b1) and bK2(b1) relations, and find that while the b2(b1) relation stays roughly unchanged, assembly bias strongly impacts the bK2(b1) relation. This impact likely extends also to the corresponding relation for galaxies, which motivates future studies to design better priors on bK2(b1) for use in cosmological constraints from galaxy clustering data.

We study and model the properties of galaxy clusters in the normal-branch Dvali–Gabadadze–Porrati (nDGP) model of gravity, which is representative of a wide class of theories that exhibit the Vainshtein screening mechanism. Using the first cosmological simulations that incorporate both full baryonic physics and nDGP, we find that, despite being efficiently screened within clusters, the fifth force can raise the temperature of the intracluster gas, affecting the scaling relations between the cluster mass and three observable mass proxies: the gas temperature, the Compton Y-parameter of the Sunyaev–Zel’dovich effect, and the X-ray analogue of the Y-parameter. Therefore, unless properly accounted for, this could lead to biased measurements of the cluster mass in tests that use cluster observations, such as cluster number counts, to probe gravity. Using a suite of dark-matter-only simulations, which span a wide range of box sizes and resolutions, and which feature very different strengths of the fifth force, we also calibrate general fitting formulae that can reproduce the nDGP halo concentration at percent accuracy for 0 ≤ z ≤ 1, and halo mass function with |${\lesssim}3{{\ \rm per\ cent}}$| accuracy at 0 ≤ z ≤ 1 (increasing to |${\lesssim}5{{\ \rm per\ cent}}$| for 1 ≤ z ≤ 2), over a halo mass range spanning four orders of magnitude. Our model for the concentration can be used for converting between halo mass overdensities and predicting statistics such as the non-linear matter power spectrum. The results of this work will form part of a framework for unbiased constraints of gravity using the data from ongoing and upcoming cluster surveys.

Six binary-merger progenitors of supernova 1987A (SN 1987A) with properties close to those of the blue supergiant Sanduleak -69°202 are exploded by neutrino heating and evolved until long after shock breakout in 3D and continued for light-curve calculations in spherical symmetry. Our results confirm previous findings for single-star progenitors: (1) 3D neutrino-driven explosions with SN 1987A-like energies synthesize ⁵⁶Ni masses consistent with the radioactive light-curve tail; (2) hydrodynamic models mix hydrogen inward to minimum velocities below 40 km s^-1 compatible with spectral observations of SN 1987A; and (3) for given explosion energy the efficiency of outward radioactive ⁵⁶Ni mixing depends mainly on high growth factors of Rayleigh-Taylor instabilities at the (C+O)/He and He/H composition interfaces and a weak interaction of fast plumes with the reverse shock occurring below the He/H interface. All binary-merger models possess presupernova radii matching the photometric radius of Sanduleak -69°202 and a structure of the outer layers allowing them to reproduce the observed initial luminosity peak in the first ~7 days. Models that mix about 0.5 M_⊙ of hydrogen into the He-shell and exhibit strong outward mixing of ⁵⁶Ni with maximum velocities exceeding the 3000 km s^-1 observed for the bulk of ejected ⁵⁶Ni have light-curve shapes in good agreement with the dome of the SN 1987A light curve. A comparative analysis of the best representatives of our 3D neutrino-driven explosion models of SN 1987A based on single-star and binary-merger progenitors reveals that only one binary model fulfills all observational constraints, except one.

We present theoretical predictions for the free-free emission at centimeter wavelengths obtained from photoevaporation and magnetohydrodynamic (MHD) wind disk models adjusted to the case of the TW Hydrae young stellar object. For this system, disk photoevaporation with heating due to the high-energy photons from the star has been proposed as a possible mechanism to open the gap observed in the dust emission with the Atacama Large Millimeter/submillimeter Array. We show that the photoevaporation disk model predicts a radial profile for the free-free emission that is made of two main spatial components, one originated from the bound disk atmosphere at 0.5-1 au from the star, and another more extended component from the photoevaporative wind at larger disk radii. We also show that the stellar X-ray luminosity has a significant impact on both these components. The predicted radio emission from the MHD wind model has a smoother radial distribution which extends to closer distances to the star than the photoevaporation case. We also show that a future radio telescope such as the Next Generation Very Large Array would have enough sensitivity and angular resolution to spatially resolve the main structures predicted by these models.

We calculate models of stellar evolution for very massive stars and include the effects of modified gravity to investigate the influence on the physical properties of blue supergiant stars and their use as extragalactic distance indicators. With shielding and fifth force parameters in a similar range as those in previous studies of Cepheid and tip of the red giant branch (TRGB) stars, we find clear effects on stellar luminosity and flux-weighted gravity. The relationship between flux-weighted gravity, g_F ≡ g/ ${T}_{\mathrm{eff}}^{4}$ , and bolometric magnitude M_bol, which has been used successfully for accurate distance determinations, is systematically affected. While the stellar evolution of flux-weighted gravity-luminosity relationships (FGLRs) show a systematic offset from the observed relation, we can use the differential shifts between models with Newtonian and modified gravity to estimate the influence on FGLR distance determinations. Modified gravity leads to an increase in distance of 0.05-0.15 magnitudes in distance modulus. These changes are comparable to the ones found for Cepheid stars. We compare observed FGLR and TRGB distances of nine galaxies to constrain the free parameters of modified gravity. Not accounting for systematic differences between TRGB and FGLR distances shielding parameters of 5 × 10^-7 and 10^-6 and fifth force parameters of 1/3 and 1 can be ruled out with about 90% confidence. Allowing for potential systematic offsets between TRGB and FGLR distances no determination is possible for a shielding parameter of 10^-6. For 5 × 10^-7 a fifth force parameter of 1 can be ruled out to 92% but 1/3 is unlikely only to 60%.

Recent millimeter and infrared observations have shown that gap- and ring-like structures are common in both dust thermal emission and scattered light of protoplanetary disks. We investigate the impact of the so-called thermal wave instability (TWI) on the millimeter and infrared scattered light images of disks. We perform 11D simulations of the TWI and confirm that the TWI operates when the disk is optically thick enough for stellar light, i.e., small-grain-to-gas mass ratio of 0.0001. The midplane temperature varies as the waves propagate, and hence gap and ring structures can be seen in both millimeter and infrared emission. The millimeter substructures can be observed even if the disk is fully optically thick since it is induced by the temperature variation, while density-induced substructures would disappear in the optically thick regime. The fractional separation between TWI-induced ring and gap is r/r 0.20.4 at 1050 au, which is comparable to those found by the Atacama Large Millimeter/submillimeter Array. Due to the temperature variation, snow lines of volatile species move radially and multiple snow lines are observed even for a single species. The wave propagation velocity is as fast as 0.6 au yr¹, which can be potentially detected with a multiepoch observation with a time separation of a few years.

Context. In 2019, the eROSITA telescope on board the Russian-German satellite Spectrum-Roentgen-Gamma (SRG) began to perform a deep all-sky X-ray survey with the aim of identifying ~100 000 clusters and groups over the course of four years. As part of its performance verification phase, a ~140 deg2 survey, called eROSITA Final Equatorial-Depth Survey (eFEDS), was performed. With a depth typical of the all-sky survey after four years, it allows tests of tools and methods as well as improved predictions for the all-sky survey.Aims. As part of this effort, a catalog of 542 X-ray selected galaxy group and cluster candidates was compiled. In this paper we present the optical follow-up, with the aim of providing redshifts and cluster confirmation for the full sample. Furthermore, we aim to provide additional information on the dynamical state, richness, and optical center of the clusters. Finally, we aim to evaluate the impact of optical cluster confirmation on the purity and completeness of the X-ray selected sample.Methods. We used optical imaging data from the Hyper Suprime-Cam Subaru Strategic Program and from the Legacy Survey to identify optical counterparts to the X-ray detected cluster candidates. We make use of the multi-component matched filter cluster confirmation tool (MCMF), as well as of the optical cluster finder CAMIRA to derive cluster redshifts and richnesses. MCMF provided the probabilities with which an optical structure would be a chance superposition with the X-ray candidate. These probabilities were used to identify the best optical counterpart as well as to confirm an X-ray candidate as a cluster. The impact of this confirmation process on catalog purity and completeness was estimated using optical to X-ray scaling relations as well as simulations. The resulting catalog was furthermore matched with public group and cluster catalogs. Optical estimators of the cluster dynamical state were constructed based on density maps of the red-sequence galaxies at the cluster redshift.Results. By providing redshift estimates for all 542 candidates, we construct an optically confirmed sample of 477 clusters and groups with a residual contamination of 6%. Of these, 470 (98.5%) are confirmed using MCMF, and 7 systems are added through cross-matching with spectroscopic group catalogs. Using observable-to-observable scaling and the applied confirmation threshold, we predict that 8 ± 2 real systems have been excluded with the MCMF cut required to build this low-contamination sample. This number agrees well with the 7 systems found through cross-matching that were not confirmed with MCMF. The predicted redshift and mass distribution of this catalog agree well with simulations. Thus, we expect that these 477 systems include >99% of all true clusters in the candidate list. Using an MCMF-independent method, we confirm that the catalog contamination of the confirmed subsample is 6 ± 3%. Application of the same method to the full candidate list yields 17 ± 3%, consistent with estimates coming from the fraction of confirmed systems of ~17% and with expectations from simulations of ~20%. We also present a sample of merging cluster candidates based on the derived estimators of the cluster dynamical state.Key words: catalogs / galaxies: clusters: general / galaxies: distances and redshifts / galaxies: clusters: intracluster medium / X-rays: galaxies: clusters★ The catalog is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/661/A4

We provide the largest and most homogeneous sample of α-element (Mg, Ca, Ti) and iron abundances for field RR Lyrae (RRLs; 162 variables) by using high-resolution spectra. The current measurements were complemented with similar abundances available in the literature for 46 field RRLs brought to our metallicity scale. We ended up with a sample of old (t ≥ 10 Gyr), low-mass stellar tracers (208 RRLs: 169 fundamental, 38 first overtone, and 1 mixed mode) covering 3 dex in iron abundance (-3.00 ≤ [Fe/H] ≤ 0.24). We found that field RRLs are ~0.3 dex more α poor than typical halo tracers in the metal-rich regime ([Fe/H] ≥ -1.2), while in the metal-poor regime ([Fe/H] ≤ -2.2) they seem to be on average ~0.1 dex more α enhanced. This is the first time that the depletion in α elements for solar iron abundances is detected on the basis of a large, homogeneous, and coeval sample of old stellar tracers. Interestingly, we also detected a close similarity in the [α/Fe] trend between α-poor, metal-rich RRLs and red giants (RGs) in the Sagittarius dwarf galaxy as well as between α-enhanced, metal-poor RRLs and RGs in ultrafaint dwarf galaxies. These results are supported by similar elemental abundances for 46 field horizontal branch stars. These stars share with RRLs the same evolutionary phase and the same progenitors. This evidence further supports the key role that old stellar tracers play in constraining the early chemical enrichment of the halo and, in particular, in investigating the impact that dwarf galaxies have had in the mass assembly of the Galaxy. * Based on observations obtained with the du Pont telescope at Las Campanas Observatory, operated by Carnegie Institution for Science. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based partly on data obtained with the STELLA robotic telescopes in Tenerife, an AIP facility jointly operated by AIP and IAC. Some of the observations reported in this paper were obtained with the Southern African Large Telescope (SALT). Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere.

Context. In November 2019, eROSITA on board of the Spektrum-Roentgen-Gamma (SRG) observatory started to map the entire sky in X-rays. After the four-year survey program, it will reach a flux limit that is about 25 times deeper than ROSAT. During the SRG performance verification phase, eROSITA observed a contiguous 140 deg2 area of the sky down to the final depth of the eROSITA all-sky survey (eROSITA Final Equatorial-Depth Survey; eFEDS), with the goal of obtaining a census of the X-ray emitting populations (stars, compact objects, galaxies, clusters of galaxies, and active galactic nuclei) that will be discovered over the entire sky.Aims. This paper presents the identification of the counterparts to the point sources detected in eFEDS in the main and hard samples and their multi-wavelength properties, including redshift.Methods. To identifyy the counterparts, we combined the results from two independent methods (NWAY and ASTROMATCH), trained on the multi-wavelength properties of a sample of 23k XMM-Newton sources detected in the DESI Legacy Imaging Survey DR8. Then spectroscopic redshifts and photometry from ancillary surveys were collated to compute photometric redshifts.Results. Of the eFEDS sources, 24 774 of 27 369 have reliable counterparts (90.5%) in the main sample and 231 of 246 sourcess (93.9%) have counterparts in the hard sample, including 2514 (3) sources for which a second counterpart is equally likely. By means of reliable spectra, Gaia parallaxes, and/or multi-wavelength properties, we have classified the reliable counterparts in both samples into Galactic (2695) and extragalactic sources (22 079). For about 340 of the extragalactic sources, we cannot rule out the possibility that they are unresolved clusters or belong to clusters. Inspection of the distributions of the X-ray sources in various optical/IR colour-magnitude spaces reveal a rich variety of diverse classes of objects. The photometric redshifts are most reliable within the KiDS/VIKING area, where deep near-infrared data are also available.Conclusions. This paper accompanies the eROSITA early data release of all the observations performed during the performance and verification phase. Together with the catalogues of primary and secondary counterparts to the main and hard samples of the eFEDS survey, this paper releases their multi-wavelength properties and redshifts.Key words: methods: data analysis / X-rays: general / catalogs / surveys / galaxies: active / galaxies: distances and redshifts★ The data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/661/A3

New neutral heavy gauge bosons (Z') are predicted within many extensions of the Standard Model. While in case they couple to quarks the LHC bounds are very stringent, leptophilic Z' bosons (even with sizable couplings) can be much lighter and therefore lead to interesting quantum effects in precision observables (like (g − 2)μ) and generate flavour violating decays of charged leptons. In particular, ℓ →ℓ 'v v ¯ decays, anomalous magnetic moments of charged leptons, ℓ → ℓ'γ and ℓ → 3ℓ' decays place stringent limits on leptophilic Z' bosons. Furthermore, in case of mixing Z' with the SM Z, Z pole observables are affected. In light of these many observables we perform a global fit to leptophilic Z' models with the main goal of finding the bounds for the Z' couplings to leptons. To this end we consider a number of scenarios for these couplings. While in generic scenarios correlations are weak, this changes once additional constraints on the couplings are imposed. In particular, if one considers an L_μ− L_τ symmetry broken only by left-handed rotations, or considers the case of τ − μ couplings only. In the latter setup, on can explain the (g − 2)_μ anomaly and the hint for lepton flavour universality violation in τ →μv v ¯/τ →ev v ¯ without violating bounds from electroweak precision observables.

We present a joint likelihood analysis of the real-space power spectrum and bispectrum measured from a variety of halo and galaxy mock catalogs. A novel aspect of this work is the inclusion of nonlinear triangle configurations for the bispectrum, made possible by a complete next-to-leading order ("one-loop") description of galaxy bias, as is already common practice for the power spectrum. Based on the goodness of fit and the unbiasedness of the parameter posteriors, we accomplish a stringent validation of this model compared to the leading order ("tree-level") bispectrum. Using measurement uncertainties that correspond to an effective survey volume of 6 (Gpc /h )³ , we determine that the one-loop corrections roughly double the applicable range of scales, from ∼0.17 h /Mpc (tree level) to ∼0.3 h /Mpc . This converts into a 1.5-2x improvement on constraints of the linear bias parameter at fixed cosmology, and a 1.5-2.4x shrinkage of uncertainties on the amplitude of fluctuations A_s, which clearly demonstrates the benefit of extracting information from nonlinear scales despite having to marginalize over a larger number of bias parameters. Besides, our precise measurements of galaxy bias parameters up to fourth order allow for thorough comparisons to coevolution relations, showing excellent agreement for all contributions generated by the nonlocal action of gravity. Using these relations in the likelihood analysis does not compromise the model validity and is crucial for obtaining the quoted improvements on A_s. We also analyzed the impact of higher-derivative and scale-dependent stochastic terms, finding that for a subset of our tracers the former can boost the performance of the tree-level model with constraints on A_s that are only slightly degraded compared to the one-loop model.

The Method of Moments is a powerful framework to disentangle the relative contributions of amplitudes of a specific process to its various phase space regions. We apply this method to carry out a fully differential analysis of the Higgs decay channel h → 4ℓ and constrain gauge-Higgs coupling modifications parametrised by dimension-six effective operators. We find that this analysis approach provides very good constraints and minimises degeneracies in the parameter space of the effective theory. By combining the decay h → 4ℓ with Higgs-associated production processes, Wh and Zh, we obtain the strongest reported bounds on anomalous gauge-Higgs couplings.

We present simulations of the multiphase interstellar medium (ISM) at solar neighbourhood conditions including thermal and non-thermal ISM processes, star cluster formation, and feedback from massive stars: stellar winds, hydrogen ionizing radiation computed with the novel TREERAY radiative transfer method, supernovae (SN), and the injection of cosmic rays (CR). N-body dynamics is computed with a 4th-order Hermite integrator. We systematically investigate the impact of stellar feedback on the self-gravitating ISM with magnetic fields, CR advection and diffusion, and non-equilibrium chemical evolution. SN-only feedback results in strongly clustered star formation with very high star cluster masses, a bi-modal distribution of the ambient SN densities, and low volume-filling factors (VFF) of warm gas, typically inconsistent with local conditions. Early radiative feedback prevents an initial starburst, reduces star cluster masses and outflow rates. Furthermore, star formation rate surface densities of $\Sigma _{\dot{M}_\star } = 1.4-5.9 \times 10^{-3}$$\mathrm{M}_\odot \, \mathrm{yr}^{-1}\, \mathrm{kpc}^{-2}$, VFF_warm = 60-80 per cent as well as thermal, kinetic, magnetic, and cosmic ray energy densities of the model including all feedback mechanisms agree well with observational constraints. On the short, 100 Myr, time-scales investigated here, CRs only have a moderate impact on star formation and the multiphase gas structure and result in cooler outflows, if present. Our models indicate that at low gas surface densities SN-only feedback only captures some characteristics of the star-forming ISM and outflows/inflows relevant for regulating star formation. Instead, star formation is regulated on star cluster scales by radiation and winds from massive stars in clusters, whose peak masses agree with solar neighbourhood estimates.

Despite the success of the Standard Model of particle physics, a number of hints suggest the existence of new physics beyond the scope of phenomena that can be explained in the theoretical

framework of the Standard Model. One class of theories that could be able to explain some of the open questions of the Standard Model is Supersymmetry. It introduces supersymmetric partners to each of the Standard Model particles, and could, for example, provide a candidate for Dark Matter. This thesis presents a search for electroweak production of supersymmetric particles in events with a lepton, missing transverse momentum and a Higgs boson decaying into two b-quarks. The search analyses 139 fb−1 of proton–proton collision data at a centre-of-mass energy of √s = 13 TeV, recorded by the ATLAS detector at the Large Hadron Collider. A likelihood-based simultaneous fit in all search regions is introduced in order to achieve sensitivity to a large variety of kinematic regimes.

We develop a formalism for computing inclusive production cross sections of heavy quarkonia based on the nonrelativistic QCD and the potential nonrelativistic QCD effective field theories. Our formalism applies to strongly coupled quarkonia, which include excited charmonium and bottomonium states. Analogously to heavy quarkonium decay processes, we express nonrelativistic QCD long-distance matrix elements in terms of quarkonium wavefunctions at the origin and universal gluonic correlators. Our expressions for the long-distance matrix elements are valid up to corrections of order $ 1/{N}_c^2 $. These expressions enhance the predictive power of the nonrelativistic effective field theory approach to inclusive production processes by reducing the number of nonperturbative unknowns, and make possible first-principle determinations of long-distance matrix elements once the gluonic correlators are known. Based on this formalism, we compute the production cross sections of P-wave charmonia and bottomonia at the LHC, and find good agreement with measurements.

Cosmogenic radio-nuclei are an important source of background for low-energy neutrino experiments. In Borexino, cosmogenic $^{11}$C decays outnumber solar pep and CNO neutrino events by about ten to one. In order to extract the flux of these two neutrino species, a highly efficient identification of this background is mandatory. We present here the details of the most consolidated strategy, used throughout Borexino solar neutrino measurements. It hinges upon finding the space-time correlations between $^{11}$C decays, the preceding parent muons and the accompanying neutrons. This article describes the working principles and evaluates the performance of this Three-Fold Coincidence (TFC) technique in its two current implementations: a hard-cut and a likelihood-based approach. Both show stable performances throughout Borexino Phases II (2012–2016) and III (2016–2020) data sets, with a $^{11}$C tagging efficiency of $\sim 90$ % and $\sim $ 63–66 % of the exposure surviving the tagging. We present also a novel technique that targets specifically $^{11}$C produced in high-multiplicity during major spallation events. Such $^{11}$C appear as a burst of events, whose space-time correlation can be exploited. Burst identification can be combined with the TFC to obtain about the same tagging efficiency of $\sim 90\%$ but with a higher fraction of the exposure surviving, in the range of $\sim $ 66–68 %.

Radiation protection is one of the critical aspects of future manned missions to the Moon, Mars, and other deep-space destinations. The precise characterization of the space radiation environment and its interaction with the spacecraft shielding is a prerequisite for protecting astronauts from the adverse health effects of radiation exposure. In this paper, we present the RadMap Telescope, a technology-demonstration experiment whose main objective is to validate new radiation-sensing concepts for applications in manned and unmanned spacecraft. It comprises a mix of newly developed and flight-proven sensors that we will use to characterize the radiation environment inside the International Space Station (ISS).

On the way of a microscopic derivation of covariant density functionals, the first complete solution of the relativistic Brueckner-Hartree-Fock (RBHF) equations is presented for symmetric nuclear matter. In most of the earlier investigations, the G-matrix is calculated only in the space of positive energy solutions. On the other side, for the solution of the relativistic Hartree-Fock (RHF) equations, also the elements of this matrix connecting positive and negative energy solutions are required. So far, in the literature, these matrix elements are derived in various approximations. We discuss solutions of the Thompson equation for the full Dirac space and compare the resulting equation of state with those of earlier attempts in this direction.

We consider matter density effects in theories with a false ground state. Large and dense systems, such as stars, can destabilize a metastable minimum and allow for the formation of bubbles of the true minimum. We derive the conditions under which these bubbles form, as well as the conditions under which they either remain confined to the dense region or escape to infinity. The latter case leads to a phase transition in the universe at star formation. We explore the phenomenological consequences of such seeded phase transitions.

Stars in the mass range from 8 M_⊙ to 10 M_⊙ are expected to produce one of two types of supernovae (SNe), either electron-capture supernovae (ECSNe) or core-collapse supernovae (CCSNe), depending on their previous evolution. Either of the associated progenitors retain extended and massive hydrogen-rich envelopes and the observables of these SNe are, therefore, expected to be similar. In this study, we explore the differences in these two types of SNe. Specifically, we investigate three different progenitor models: a solar-metallicity ECSN progenitor with an initial mass of 8.8 M_⊙, a zero-metallicity progenitor with 9.6 M_⊙, and a solar-metallicity progenitor with 9 M_⊙, carrying out radiative transfer simulations for these progenitors. We present the resulting light curves for these models. The models exhibit very low photospheric velocity variations of about 2000 km s^-1; therefore, this may serve as a convenient indicator of low-mass SNe. The ECSN has very unique light curves in broad-bands, especially the U band, and does not resemble any currently observed SN. This ECSN progenitor being part of a binary will lose its envelope for which reason the light curve becomes short and undetectable. The SN from the 9.6 M_⊙ progenitor exhibits also quite an unusual light curve, explained by the absence of metals in the initial composition. The artificially iron-polluted 9.6 M_⊙ model demonstrates light curves closer to normal SNe IIP. The SN from the 9 M_⊙ progenitor remains the best candidate for so-called low-luminosity SNe IIP like SN 1999br and SN 2005cs.

We present the first application of the extended Fast Action Minimization method (eFAM) to a real data set, the SDSS-DR12 Combined Sample, to reconstruct galaxies orbits back-in-time, their two-point correlation function (2PCF) in real-space, and enhance the baryon acoustic oscillation (BAO) peak. For this purpose, we introduce a new implementation of eFAM that accounts for selection effects, survey footprint, and galaxy bias. We use the reconstructed BAO peak to measure the angular diameter distance, $D_\mathrm{A}(z)r^\mathrm{fid}_\mathrm{s}/r_\mathrm{s}$ , and the Hubble parameter, $H(z)r_\mathrm{s}/r^\mathrm{fid}_\mathrm{s}$ , normalized to the sound horizon scale for a fiducial cosmology $r^\mathrm{fid}_\mathrm{s}$ , at the mean redshift of the sample z = 0.38, obtaining $D_\mathrm{A}(z=0.38)r^\mathrm{fid}_\mathrm{s}/r_\mathrm{s}=1090\pm 29$ (Mpc)^-1, and $H(z=0.38)r_\mathrm{s}/r^\mathrm{fid}_\mathrm{s}=83\pm 3$ (km s^-1 Mpc^-1), in agreement with previous measurements on the same data set. The validation tests, performed using 400 publicly available SDSS-DR12 mock catalogues, reveal that eFAM performs well in reconstructing the 2PCF down to separations of ∼25h^-1Mpc, i.e. well into the non-linear regime. Besides, eFAM successfully removes the anisotropies due to redshift-space distortion (RSD) at all redshifts including that of the survey, allowing us to decrease the number of free parameters in the model and fit the full-shape of the back-in-time reconstructed 2PCF well beyond the BAO peak. Recovering the real-space 2PCF, eFAM improves the precision on the estimates of the fitting parameters. When compared with the no-reconstruction case, eFAM reduces the uncertainty of the Alcock-Paczynski distortion parameters α_⊥ and α_∥ of about 40 per cent and that on the non-linear damping scale Σ_∥ of about 70 per cent. These results show that eFAM can be successfully applied to existing redshift galaxy catalogues and should be considered as a reconstruction tool for next-generation surveys alternative to popular methods based on the Zel'dovich approximation.

We present cosmological zoom-in hydrodynamical simulations for the formation of disc galaxies, implementing dust evolution and dust promoted cooling of hot gas. We couple an improved version of our previous treatment of dust evolution, which adopts the two-size approximation to estimate the grain-size distribution, with the MUPPI star formation and feedback subresolution model. Our dust evolution model follows carbon and silicate dust separately. To distinguish differences induced by the chaotic behaviour of simulations from those genuinely due to different simulation set-up, we run each model six times, after introducing tiny perturbations in the initial conditions. With this method, we discuss the role of various dust-related physical processes and the effect of a few possible approximations adopted in the literature. Metal depletion and dust cooling affect the evolution of the system, causing substantial variations in its stellar, gas, and dust content. We discuss possible effects on the Spectral Energy Distribution of the significant variations of the size distribution and chemical composition of grains, as predicted by our simulations during the evolution of the galaxy. We compare dust surface density, dust-to-gas ratio, and small-to-large grain mass ratio as a function of galaxy radius and gas metallicity predicted by our fiducial run with recent observational estimates for three disc galaxies of different masses. The general agreement is good, in particular taking into account that we have not adjusted our model for this purpose.

We showed how to use trained neural networks to perform Bayesian reasoning in order to solve tasks outside their initial scope. Deep generative models provide prior knowledge, and classification/regression networks impose constraints. The tasks at hand were formulated as Bayesian inference problems, which we approximately solved through variational or sampling techniques. The approach built on top of already trained networks, and the addressable questions grew super-exponentially with the number of available networks. In its simplest form, the approach yielded conditional generative models. However, multiple simultaneous constraints constitute elaborate questions. We compared the approach to specifically trained generators, showed how to solve riddles, and demonstrated its compatibility with state-of-the-art architectures.

We present here a self-consistent cosmological zoom-in simulation of a triple supermassive black hole (SMBH) system forming in a complex multiple galaxy merger. The simulation is run with an updated version of our code KETJU, which is able to follow the motion of SMBHs down to separations of tens of Schwarzschild radii while simultaneously modeling the large-scale astrophysical processes in the surrounding galaxies, such as gas cooling, star formation, and stellar and AGN feedback. Our simulation produces initially an SMBH binary system for which the hardening process is interrupted by the late arrival of a third SMBH. The KETJU code is able to accurately model the complex behavior occurring in such a triple SMBH system, including the ejection of one SMBH to a kiloparsec-scale orbit in the galaxy due to strong three-body interactions as well as Lidov-Kozai oscillations suppressed by relativistic precession when the SMBHs are in a hierarchical configuration. One pair of SMBHs merges ∼3 Gyr after the initial galaxy merger, while the remaining binary is at a parsec-scale separation when the simulation ends at redshift z = 0. We also show that KETJU can capture the effects of the SMBH binaries and triplets on the surrounding stellar population, which can affect the binary merger timescales as the stellar density in the system evolves. Our results demonstrate the importance of dynamically resolving the complex behavior of multiple SMBHs in galactic mergers, as such systems cannot be readily modeled using simple orbit-averaged semianalytic models.

Parametric and non-parametric classifiers often have to deal with real-world data, where corruptions like noise, occlusions, and blur are unavoidable - posing significant challenges. We present a probabilistic approach to classify strongly corrupted data and quantify uncertainty, despite the model only having been trained with uncorrupted data. A semi-supervised autoencoder trained on uncorrupted data is the underlying architecture. We use the decoding part as a generative model for realistic data and extend it by convolutions, masking, and additive Gaussian noise to describe imperfections. This constitutes a statistical inference task in terms of the optimal latent space activations of the underlying uncorrupted datum. We solve this problem approximately with Metric Gaussian Variational Inference (MGVI). The supervision of the autoencoder's latent space allows us to classify corrupted data directly under uncertainty with the statistically inferred latent space activations. Furthermore, we demonstrate that the model uncertainty strongly depends on whether the classification is correct or wrong, setting a basis for a statistical "lie detector" of the classification. Independent of that, we show that the generative model can optimally restore the uncorrupted datum by decoding the inferred latent space activations.

The frequency of Earth-sized planets in habitable zones appears to be higher around M-dwarfs, making these systems exciting laboratories to investigate planet formation. Observations of protoplanetary disks around very low-mass stars and brown dwarfs remain challenging and little is known about their properties. The disk around CIDA 1 (~0.1-0.2 M_⊙) is one of the very few known disks that host a large cavity (20 au radius in size) around a very low-mass star. We present new ALMA observations at Band 7 (0.9 mm) and Band 4 (2.1 mm) of CIDA 1 with a resolution of ~0.05″ × 0.034″. These new ALMA observations reveal a very bright and unresolved inner disk, a shallow spectral index of the dust emission (~2), and a complex morphology of a ring located at 20 au. We also present X-shooter (VLT) observations that confirm the high accretion rate of CIDA 1 of Ṁ_acc = 1.4 × 10⁻⁸ M_⊙ yr⁻¹. This high value of Ṁ_acc, the observed inner disk, and the large cavity of 20 au exclude models of photo-evaporation to explain the observed cavity. When comparing these observations with models that combine planet-disk interaction, dust evolution, and radiative transfer, we exclude planets more massive than 0.5 M_Jup as the potential origin of the large cavity because with these it is difficult to maintain a long-lived and bright inner disk. Even in this planet mass regime, an additional physical process may be needed to stop the particles from migrating inwards and to maintain a bright inner disk on timescales of millions of years. Such mechanisms include a trap formed by a very close-in extra planet or the inner edge of a dead zone. The low spectral index of the disk around CIDA 1 is difficult to explain and challenges our current dust evolution models, in particular processes like fragmentation, growth, and diffusion of particles inside pressure bumps.

We solve the Lindblad equation describing the Brownian motion of a Coulombic heavy quark-antiquark pair in a strongly coupled quark-gluon plasma using the highly efficient Monte Carlo wave-function method. The Lindblad equation has been derived in the framework of pNRQCD and fully accounts for the quantum and non-Abelian nature of the system. The hydrodynamics of the plasma is realistically implemented through a 3+1D dissipative hydrodynamics code. We compute the bottomonium nuclear modification factor and compare with the most recent LHC data. The computation does not rely on any free parameter, as it depends on two transport coefficients that have been evaluated independently in lattice QCD. Our final results, which include late-time feed down of excited states, agree well with the available data from LHC 5.02 TeV PbPb collisions.

We report the serendipitous detection of an H₂-bearing damped Lyα absorber at z = 0.576 in the spectrum of the QSO J0111-0316 in the Cosmic Ultraviolet Baryon Survey. Spectroscopic observations from Hubble Space Telescope-COS in the far-ultraviolet reveal a damped absorber with log[N(H I)/cm^-2] = 20.1 ± 0.2 and log[N(H₂)/cm^-2] $={18.97}_{-0.06}^{+0.05}$ . The diffuse molecular gas is found in two velocity components separated by Δ ν ≍ 60 km s^-1, with >99.9% of the total H₂ column density concentrated in one component. At a metallicity of ≍50% of solar, there is evidence for Fe enhancement and dust depletion, with a dust-to-gas ratio κ_O ≍ 0.4. A galaxy redshift survey conducted with IMACS and LDSS-3C on Magellan reveals an overdensity of nine galaxies at projected distance d ≤ 600 proper kpc (pkpc) and line-of-sight velocity offset Δ ν_g ≤ 300 km s^-1 from the absorber. The closest is a massive, early-type galaxy at d = 41 pkpc that contains ≍70% of the total stellar mass identified at d ≤ 310 pkpc of the H₂ absorber. The close proximity of the H₂-bearing gas to the quiescent galaxy and the Fe-enhanced chemical abundance pattern of the absorber suggest a physical connection, in contrast to a picture in which DLAs are primarily associated with gas-rich dwarfs. This case study illustrates that deep galaxy redshift surveys are needed to gain insight into the diverse environments that host dense and potentially star-forming gas. * Based on data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory and the NASA/ESA Hubble Space Telescope operated by the Space Telescope Science Institute and the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

We use field-level forward models of galaxy clustering and the EFT likelihood formalism to study, for the first time for self-consistently simulated galaxies, the relations between the linear b_1 and second-order bias parameters b 2 and b K 2 . The forward models utilize all of the information available in the galaxy distribution up to a given order in perturbation theory, which allows us to infer these bias parameters with high signal-to-noise, even from relatively small volumes (L box = 205 Mpc/h). We consider galaxies from the simulations, and our main result is that the b 2(b 1) and b K 2 (b 1) relations obtained from gravity-only simulations for total mass selected objects are broadly preserved for simulated galaxies selected by stellar mass, star formation rate, color and black hole accretion rate. We also find good agreement between the bias relations of the simulated galaxies and a number of recent estimates for observed galaxy samples. The consistency under different galaxy selection criteria suggests that theoretical priors on these bias relations may be used to improve cosmological constraints based on observed galaxy samples. We do identify some small differences between the bias relations in the hydrodynamical and gravity-only simulations, which we show can be linked to the environmental dependence of the relation between galaxy properties and mass. We also show that the EFT likelihood recovers the value of σ8 to percent-level from various galaxy samples (including splits by color and star formation rate) and after marginalizing over 8 bias parameters. This demonstration using simulated galaxies adds to previous works based on halos as tracers, and strengthens further the potential of forward models to infer cosmology from galaxy data.

We study the approach to scaling in axion string networks in the radiation era, through measuring the root-mean-square velocity v as well as the scaled mean string separation x . We find good evidence for a fixed point in the phase-space analysis in the variables (x ,v ), providing a strong indication that standard scaling is taking place. We show that the approach to scaling can be well described by a two parameter velocity-one-scale (VOS) model, and show that the values of the parameters are insensitive to the initial state of the network. The string length has also been commonly expressed in terms of a dimensionless string length density ζ , proportional to the number of Hubble lengths of string per Hubble volume. In simulations with initial conditions far from the fixed point ζ is still evolving after half a light-crossing time, which has been interpreted in the literature as a long-term logarithmic growth. We show that all our simulations, even those starting far from the fixed point, are accounted for by a VOS model with an asymptote of ζ_*=1.20 ±0.09 (calculated from the string length in the cosmic rest frame) and v_*=0.609 ±0.014 .

New physics not far above the TeV scale should leave a pattern of virtual effects in observables at lower energies. What do these effects tell us about the flavor structure of a UV theory? Within the framework of Standard Model Effective Field Theory (SMEFT), we resolve the flavor structure of the Wilson coefficients in a combined analysis of top-quark and B-physics observables. Our fit to LHC and b-factory measurements shows that combining top and bottom observables is crucial to pin down possible sources of flavor symmetry breaking from UV physics. Our analysis includes the full analytic expansion of SMEFT coefficients in Minimal Flavor Violation and a detailed study of SMEFT effects in b→s flavor transitions.

High-redshift star-forming galaxies have very different morphologies compared to nearby ones. Indeed, they are often dominated by bright star-forming structures of masses up to 10^8-9 M_⊙ dubbed 'giant clumps'. However, recent observations questioned this result by showing only low-mass structures or no structure at all. We use Adaptative Mesh Refinement hydrodynamical simulations of galaxies with parsec-scale resolution to study the formation of structures inside clumpy high-redshift galaxies. We show that in very gas-rich galaxies star formation occurs in small gas clusters with masses below 10^7-8 M_⊙ that are themselves located inside giant complexes with masses up to 10⁸ and sometimes 10⁹ M_⊙. Those massive structures are similar in mass and size to the giant clumps observed in imaging surveys, in particular with the Hubble Space Telescope. Using mock observations of simulated galaxies, we show that at very high resolution with instruments like the Atacama Large Millimeter Array or through gravitational lensing, only low-mass structures are likely to be detected, and their gathering into giant complexes might be missed. This leads to the non-detection of the giant clumps and therefore introduces a bias in the detection of these structures. We show that the simulated giant clumps can be gravitationally bound even when undetected in mocks representative for ALMA observations and HST observations of lensed galaxies. We then compare the top-down fragmentation of an initially warm disc and the bottom-up fragmentation of an initially cold disc to show that the process of formation of the clumps does not impact their physical properties.

We use a modified version of the peak patch excursion set formalism to compute the mass and size distribution of QCD axion miniclusters from a fully non-Gaussian initial density field obtained from numerical simulations of axion string decay. We find strong agreement with N -body simulations at significantly lower computational cost. We employ a spherical collapse model, and provide fitting functions for the modified barrier in the radiation era. The halo mass function at z =629 has a power-law distribution M^-0.6 for masses within the range 10^-15≲M ≲10^-10 M_⊙ , with all masses scaling as (m_a/50 μ eV )^-0.5 . We construct merger trees to estimate the collapse redshift and concentration mass relation, C (M ), which is well described using analytical results from the initial power spectrum and linear growth. Using the calibrated analytic results to extrapolate to z =0 , our method predicts a mean concentration C ∼O (few )×10⁴. The low computational cost of our method makes future investigation of the statistics of rare, dense miniclusters easy to achieve.

We present a novel hierarchical formulation of the fourth-order forward symplectic integrator and its numerical implementation in the GPU-accelerated direct-summation N-body code frost. The new integrator is especially suitable for simulations with a large dynamical range due to its hierarchical nature. The strictly positive integrator sub-steps in a fourth-order symplectic integrator are made possible by computing an additional gradient term in addition to the Newtonian accelerations. All force calculations and kick operations are synchronous so the integration algorithm is manifestly momentum-conserving. We also employ a time-step symmetrization procedure to approximately restore the time-reversibility with adaptive individual time-steps. We demonstrate in a series of binary, few-body and million-body simulations that frost conserves energy to a level of |ΔE/E| ∼ 10^-10 while errors in linear and angular momentum are practically negligible. For typical star cluster simulations, we find that frost scales well up to $N_\mathrm{GPU}^\mathrm{max}\sim 4\times N/10^5$ GPUs, making direct-summation N-body simulations beyond N = 10⁶ particles possible on systems with several hundred and more GPUs. Due to the nature of hierarchical integration, the inclusion of a Kepler solver or a regularized integrator with post-Newtonian corrections for close encounters and binaries in the code is straightforward.

An analytical chemical evolution model is constructed to investigate the radial distribution of gas-phase and stellar metallicity for star-forming galaxies. By means of the model, the gas-phase and stellar metallicity can be obtained from the stellar-to-gas mass ratio. Both the gas inflow and outflow processes play an important role in building the final gas-phase metallicity, and there exists degeneracy effect between the gas inflow and outflow rates for star-forming galaxies. On the other hand, stellar metallicity is more sensitive to the gas outflow rate than to the gas inflow rate, and this helps to break the parameter degeneracy for star-forming galaxies. We apply this analysis method to the nearby disc galaxy M 101 and adopting the classical χ² methodology to explore the influence of model parameters on the resulted metallicity. It can be found that the combination of gas-phase and stellar metallicity is indeed more effective for constraining the gas inflow and outflow rates. Our results also show that the model with relatively strong gas outflows but weak gas inflow describes the evolution of M 101 reasonably well.

Context. The Carina Nebula harbors a large population of high-mass stars, including at least 75 O-type and Wolf-Rayet (WR) stars, but the current census is not complete since further high-mass stars may be hidden in or behind the dense dark clouds that pervade the association.
Aims: With the aim of identifying optically obscured O- and early B-type stars in the Carina Nebula, we performed the first infrared spectroscopic study of stars in the optically obscured stellar cluster Tr 16-SE, located behind a dark dust lane south of η Car.
Methods: We used the integral-field spectrograph KMOS at the ESO VLT to obtain H- and K-band spectra with a resolution of R ≈ 4000 (Δλ ≈ 5 Å) for 45 out of the 47 possible OB candidate stars in Tr 16-SE, and we derived spectral types for these stars.
Results: We find 15 stars in Tr 16-SE with spectral types between O5 and B2 (i.e., high-mass stars with M ≥ 8 M_⊙), only two of which were known before. An additional nine stars are classified as (Ae)Be stars (i.e., intermediate-mass pre-main-sequence stars), and most of the remaining targets show clear signatures of being late-type stars and are thus most likely foreground stars or background giants unrelated to the Carina Nebula. Our estimates of the stellar luminosities suggest that nine of the 15 O- and early B-type stars are members of Tr 16-SE, whereas the other six seem to be background objects.
Conclusions: Our study increases the number of spectroscopically identified high-mass stars (M ≥ 8 M_⊙) in Tr 16-SE from two to nine and shows that Tr 16-SE is one of the larger clusters in the Carina Nebula. Our identification of three new stars with spectral types between O5 and O7 and four new stars with spectral types O9 to B1 significantly increases the number of spectroscopically identified O-type stars in the Carina Nebula.

Reduced spectra are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/648/A34

Based on observations collected at the European Southern Observatory under ESO program 097.C-0102.

NonGaussian cosmic shear statistics based on weak-lensing aperture mass (M_ap) maps can outperform the classical shear two-point correlation function (γ-2PCF) in terms of cosmological constraining power. However, reaching the full potential of these new estimators requires accurate modeling of the physics of baryons as the extra nonGaussian information mostly resides at small scales. We present one such modeling based on the Magneticum hydrodynamical simulation for the KiDS-450 and DES-Y1 surveys and a Euclid-like survey. We compute the bias due to baryons on the lensing PDF and the distribution of peaks and voids in M_ap maps and propagate it to the cosmological forecasts on the structure growth parameter S₈, the matter density parameter Ω_m, and the dark energy equation of state w₀ using the SLICS and cosmo-SLICS sets of dark-matter-only simulations. We report a negative bias of a few percent on S₈ and Ω_m and also measure a positive bias of the same level on w₀ when including a tomographic decomposition. These biases reach ∼5% when combining M_ap statistics with the γ-2PCF as these estimators show similar dependency on the AGN feedback. We verify that these biases constitute a less than 1σ shift on the probed cosmological parameters for current cosmic shear surveys. However, baryons need to be accounted for at the percentage level for future Stage IV surveys and we propose to include the uncertainty on the AGN feedback amplitude by marginalizing over this parameter using multiple simulations such as those presented in this paper. Finally, we explore the possibility of mitigating the impact of baryons by filtering the M_ap map but find that this process would require suppressing the small-scale information to a point where the constraints would no longer be competitive.

Supernova spectral time series contain a wealth of information about the progenitor and explosion process of these energetic events. The modeling of these data requires the exploration of very high dimensional posterior probabilities with expensive radiative transfer codes. Even modest parameterizations of supernovae contain more than 10 parameters and a detailed exploration demands at least several million function evaluations. Physically realistic models require at least tens of CPU minutes per evaluation putting a detailed reconstruction of the explosion out of reach of traditional methodology. The advent of widely available libraries for the training of neural networks combined with their ability to approximate almost arbitrary functions with high precision allows for a new approach to this problem. Instead of evaluating the radiative transfer model itself, one can build a neural network proxy trained on the simulations but evaluating orders of magnitude faster. Such a framework is called an emulator or surrogate model. In this work, we present an emulator for the TARDIS supernova radiative transfer code applied to Type Ia supernova spectra. We show that we can train an emulator for this problem given a modest training set of 100,000 spectra (easily calculable on modern supercomputers). The results show an accuracy on the percent level (that are dominated by the Monte Carlo nature of TARDIS and not the emulator) with a speedup of several orders of magnitude. This method has a much broader set of applications and is not limited to the presented problem.

Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42 <L <117 MeV . This value is slightly lower but consistent with the L values deduced from a recent measurement of the neutron skin thickness of ²⁰⁸Pb.

We analyse from an observational perspective the formation history and kinematics of a Milky Way-like galaxy from a high-resolution zoom-in cosmological simulation that we compare to those of our Galaxy as seen by Gaia DR2 to better understand the origin and evolution of the Galactic thin and thick discs. The cosmological simulation was carried out with the GADGET-3 TreePM+SPH code using the MUlti-Phase Particle Integrator (MUPPI) model. We disentangle the complex overlapping of stellar generations that rises from the top-down and inside-out formation of the galactic disc. We investigate cosmological signatures in the phase-space of mono-age populations and highlight features stemming from past and recent dynamical perturbations. In the simulation, we identify a satellite with a stellar mass of $1.2 \times 10^9~\rm {M}_\odot$ , i.e. stellar mass ratio Δ ∼ 5.5 per cent at the time, accreted at z ∼ 1.6, which resembles the major merger Gaia-Sausage-Enceladus that produced the Galactic thick disc, i.e. Δ ∼ 6 per cent. We found at z ∼ 0.5-0.4 two merging satellites with a stellar mass of $8.8 \times 10^8~\rm {M}_\odot$ and $5.1 \times 10^8~\rm {M}_\odot$ that are associated to a strong starburst in the star formation history, which appears fairly similar to that recently found in the solar neighbourhood. Our findings highlight that detailed studies of coeval stellar populations kinematics, which are made available by current and future Gaia data releases and in synergy with simulations, are fundamental to unravel the formation and evolution of the Milky Way discs.

We construct empirical models of star-forming galaxy evolution assuming that individual galaxies evolve along well-known scaling relations between stellar mass, gas mass, and star formation rate following a simple description of chemical evolution. We test these models by a comparison with observations and detailed Magneticum high-resolution hydrodynamic cosmological simulations. Galaxy star formation rates, stellar masses, gas masses, ages, interstellar medium, and stellar metallicities are compared. It is found that these simple look-back models capture many of the crucial aspects of galaxy evolution reasonably well. Their key assumption of a redshift-dependent power-law relationship between galaxy interstellar medium gas mass and stellar mass is in agreement with the outcome of the complex Magneticum simulations. Star formation rates decline toward lower redshift not because galaxies are running out of gas, but because the fraction of the cold interstellar medium gas, which is capable of producing stars, becomes significantly smaller. Gas accretion rates in both model approaches are of the same order of magnitude. Metallicity in the Magneticum simulations increases with the ratio of stellar mass to gas mass as predicted by the look-back models. The mass-metallicity relationships agree, and the star formation rate dependence of these relationships is also reproduced. We conclude that these simple models provide a powerful tool for constraining and interpreting more complex models based on cosmological simulations and for population synthesis studies analyzing the integrated spectra of stellar populations.

The Standard Model of Particle Physics predicts the double-β decay of certain nuclei with the emission of two active neutrinos. In this letter, we argue that double-β decay experiments could be used to probe models with light exotic fermions through the search for spectral distortions in the electron spectrum with respect to the Standard Model expectations. We consider two concrete examples: models with light sterile neutrinos, singly produced in the double-β decay, and models with a light Z₂-odd fermion, pair produced due to a Z₂ symmetry. We estimate the discovery potential of a selection of double-β decay experiments and find that future searches will test for the first time a new part of the parameter space of interest at the MeV-mass scale.

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.

Mid-infrared imaging traces the sub-micron and micron sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have circumplanetary disks. We use the VISIR instrument and its upgrade NEAR on the VLT to take new mid-infrared images of five (pre-)transition disks and one circumstellar disk with proposed planets and obtain the deepest resolved mid-infrared observations to date in order to put new constraints on the sizes of the emitting regions of the disks and the presence of possible companions. We derotate and stack the data to find the disk properties. Where available we compare the data to ProDiMo (Protoplanetary Disk Model) radiation thermo-chemical models to achieve a deeper understanding of the underlying physical processes within the disks. We apply the circularised PSF subtraction method to find upper limits on the fluxes of possible companions and model companions with circumplanetary disks. We resolve three of the six disks and calculate position angles, inclinations and (upper limits to) sizes of emission regions in the disks, improving upper limits on two of the unresolved disks. In all cases the majority of the mid-IR emission comes from small inner disks or the hot inner rims of outer disks. We refine the existing ProDiMo HD 100546 model SED fit in the mid-IR by increasing the PAH abundance relative to the ISM, adopting coronene as the representative PAH, and increase the outer cavity radius to 22.3 AU. We produce flux estimates for putative planetary-mass companions and circumplanetary disks, ruling out the presence of planetary-mass companions with L>0.0028L⊙ for a>180 AU in the HD 100546 system. Upper limits of 0.5 mJy-30 mJy are obtained at 8 μm-12 μm for potential companions in the different disks.

Our current knowledge about the Moon’s resource potential is limited to remote-sensing measurements and the analysis of Apollo-era samples. Even though there are persistent indications for substantial deposits of water and other volatiles—especially in the lunar polar regions—high-resolution mapping and in situ measurements are required to assess the technical feasibility and economic viability of exploiting them. The LUVMI-X mission will use a 50-kg rover equipped with complementary instrumentation to prospect illuminated and shadowed areas in the Moon’s polar regions through the use of laser spectroscopy, neutron spectroscopy, and direct sampling in combination with mass spectroscopy. It will also analyze the regolith composition and characterize the surface radiation environment.

Light axionlike particles occur in many theories of beyond-Standard-Model physics, and may make up some or all of the Universe's dark matter. One of the ways they can couple to the Standard Model is through the electromagnetic F_{μ ν}F^{∼μ ν} portal, and there is a broad experimental program, covering many decades in mass range, aiming to search for axion dark matter via this coupling. In this paper, we derive limits on the absorbed power, and coupling sensitivity, for a broad class of such searches. We find that standard techniques, such as resonant cavities and dielectric haloscopes, can achieve O (1 )-optimal axion-mass-averaged signal powers, for given volume and magnetic field. For low-mass (frequency ≪GHz ) axions, experiments using static background magnetic fields generally have suppressed sensitivity; we discuss the physics of this limitation, and propose experimental methods to avoid it, such as microwave up-conversion experiments. We also comment on the detection of other forms of dark matter, including dark photons, as well as the detection of relativistic hidden-sector particles.

We observed the K7 class III star NO Lup in an ALMA survey of the 1-3 Myr Lupus association and detected circumstellar dust and CO gas. Here we show that the J = 3-2 CO emission is both spectrally and spatially resolved, with a broad velocity width ~19 km s^-1 for its resolved size ~1 arcsec (~130 au). We model the gas emission as a Keplerian disc, finding consistency, but only with a central mass of ~11M_⊙, which is implausible given its spectral type and X-Shooter spectrum. A good fit to the data can also be found by modelling the CO emission as outflowing gas with a radial velocity ~22 km s^-1. We interpret NO Lup's CO emission as the first imaged class III circumstellar disc with outflowing gas. We conclude that the CO is continually replenished, but cannot say if this is from the breakup of icy planetesimals or from the last remnants of the protoplanetary disc. We suggest further work to explore the origin of this CO, and its higher than expected velocity in comparison to photoevaporative models.

We present an effective model for the one-dimensional Lyman-α flux power spectrum far above the baryonic Jeans scale. The main new ingredient is constituted by a set of two parameters that encode the impact of small, highly non-linear scales on the one-dimensional power spectrum on large scales, where it is measured by BOSS. We show that, by marginalizing over the model parameters that capture the impact of the intergalactic medium, the flux power spectrum from both simulations and observations can be described with high precision. The model displays a degeneracy between the neutrino masses and the (unknown, in our formalism) normalization of the flux power spectrum. This degeneracy can be lifted by calibrating one of the model parameters with simulation data, and using input from Planck CMB data. We demonstrate that this approach can be used to extract bounds on the sum of neutrino masses with comparably low numerical effort, while allowing for a conservative treatment of uncertainties from the dynamics of the intergalactic medium. An explorative analysis yields an upper bound of 0.16eV at 95% C.L. when applied to BOSS data at 3 ≤ z ≤ 4.2. We also forecast that if the systematic and statistical errors will be reduced by a factor two the upper bound will become 0.1eV at 95% C.L, and 0.056eV when assuming a 1% error.

We establish that unitarity of scattering amplitudes imposes universal entropy bounds. The maximal entropy of a self-sustained quantum field object of radius R is equal to its surface area and at the same time to the inverse running coupling α evaluated at the scale R. The saturation of these entropy bounds is in one-to-one correspondence with the non-perturbative saturation of unitarity by 2 → N particle scattering amplitudes at the point of optimal truncation. These bounds are more stringent than Bekenstein’s bound and in a consistent theory all three get saturated simultaneously. This is true for all known entropy-saturating objects such as solitons, instantons, baryons, oscillons, black holes or simply lumps of classical fields. We refer to these collectively as saturons and show that in renormalizable theories they behave in all other respects like black holes. Finally, it is argued that the confinement in SU(N) gauge theory can be understood as a direct consequence of the entropy bounds and unitarity.

We analyse the gas content evolution of infalling haloes in cluster environments from The Three Hundred project, a collection of 324 numerically modelled galaxy clusters. The haloes in our sample were selected within 5R₂₀₀ of the main cluster halo at $z$ = 0 and have total halo mass M₂₀₀ ≥ 10¹¹h^-1M_⊙. We track their main progenitors and study their gas evolution since their crossing into the infall region, which we define as 1-4R₂₀₀. Studying the radial trends of our populations using both the full phase-space information and a line-of-sight projection, we confirm the Arthur et al. (2019) result and identify a characteristic radius around 1.7R₂₀₀ in 3D and at R₂₀₀ in projection at which infalling haloes lose nearly all of the gas prior their infall. Splitting the trends by subhalo status,we show that subhaloes residing in group-mass and low-mass host haloes in the infall region follow similar radial gas-loss trends as their hosts, whereas subhaloes of cluster-mass host haloes are stripped of their gas much further out. Our results show that infalling objects suffer significant gaseous disruption that correlates with time-since-infall, cluster-centric distance, and host mass, and that the gaseous disruption they experience is a combination of subhalo pre-processing and object gas depletion at a radius that behaves like an accretion shock.

Wavelength selection in reaction-diffusion systems can be understood as a coarsening process that is interrupted by counteracting processes at certain wavelengths. We first show that coarsening in mass-conserving systems is driven by self-amplifying mass transport between neighboring high-density domains. We derive a general coarsening criterion and show that coarsening is generically uninterrupted in two-component systems that conserve mass. The theory is then generalized to study interrupted coarsening and anticoarsening due to weakly broken mass conservation, providing a general path to analyze wavelength selection in pattern formation far from equilibrium.

We combine orbital information from N-body simulations with an analytic model for star formation quenching and SDSS observations to infer the differential effect of the group/cluster environment on star formation in satellite galaxies. We also consider a model for gas stripping, using the same input supplemented with H I fluxes from the ALFALFA survey. The models are motivated by and tested on the Hydrangea cosmological hydrodynamical simulation suite. We recover the characteristic times when satellite galaxies are stripped and quenched. Stripping in massive ($M_{\rm vir}\sim 10^{14.5}\, {\rm M}_\odot$) clusters typically occurs at or just before the first pericentric passage. Lower mass ($\sim 10^{13.5}\, {\rm M}_\odot$) groups strip their satellites on a significantly longer (by $\sim 3\, {\rm Gyr}$) time-scale. Quenching occurs later: Balmer emission lines typically fade $\sim 3.5\, {\rm Gyr}$ ($5.5\, {\rm Gyr}$) after first pericentre in clusters (groups), followed a few hundred Myr later by reddenning in (g - r) colour. These 'delay time-scales' are remarkably constant across the entire satellite stellar mass range probed (~10^9.5-$10^{11}\, {\rm M}_\odot$), a feature closely tied to our treatment of 'group pre-processing'. The lowest mass groups in our sample ($\sim 10^{12.5}\, {\rm M}_\odot$) strip and quench their satellites extremely inefficiently: typical time-scales may approach the age of the Universe. Our measurements are qualitatively consistent with the 'delayed-then-rapid' quenching scenario advocated for by several other studies, but we find significantly longer delay times. Our combination of a homogeneous analysis and input catalogues yields new insight into the sequence of events leading to quenching across wide intervals in host and satellite mass.

From 22 to 26 June 2020, we hosted ESO's first live e-conference, #H02020, from within ESO headquarters in Garching, Germany. Every day, between 200 and 320 researchers around the globe tuned in to discuss the nature and implications of the discord between precise determinations of the Universe's expansion rate, H0. Originally planned as an in-person meeting, we moved to the virtual domain to maintain strong scientific discourse despite the SARS-CoV-2 (COVID-19) pandemic. Here, we describe our conference setup, participants feedback gathered before and after the meeting, and lessons learned from this unexpected exercise. As e-conferencing will become increasingly common in the future, we provide our perspective on how e-conferences can make scientific exchange more effective and inclusive, in addition to climate friendly.

Cosmological inference from cluster number counts is systematically limited by the accuracy of the mass calibration, i.e. the empirical determination of the mapping between cluster selection observables and halo mass. In this work we demonstrate a method to quantitatively determine the bias and uncertainties in weak-lensing (WL) mass calibration. To this end, we extract a library of projected matter density profiles from hydrodynamical simulations. Accounting for shear bias and noise, photometric redshift uncertainties, mis-centreing, cluster member contamination, cluster morphological diversity, and line-of-sight projections, we produce a library of shear profiles. Fitting a one-parameter model to these profiles, we extract the so-called WL mass M_WL. Relating the WL mass to the halo mass from gravity-only simulations with the same initial conditions as the hydrodynamical simulations allows us to estimate the impact of hydrodynamical effects on cluster number counts experiments. Creating new shear libraries for ∼1000 different realizations of the systematics provides a distribution of the parameters of the WL to halo mass relation, reflecting their systematic uncertainty. This result can be used as a prior for cosmological inference. We also discuss the impact of the inner fitting radius on the accuracy, and determine the outer fitting radius necessary to exclude the signal from neighbouring structures. Our method is currently being applied to different Stage III lensing surveys, and can easily be extended to Stage IV lensing surveys.

To understand the history and formation mechanisms of galaxies, it is crucial to determine their current multidimensional structure. In this work, we focus on the properties that characterise stellar populations, such as metallicity and [α/Fe] enhancement. We devised a new technique to recover the distribution of these parameters using spatially resolved, line-of-sight averaged data. Our chemodynamical method is based on the made-to-measure framework and results in an N-body model for the abundance distribution. Following a test on a mock data set we found that the radial and azimuthal profiles were well-recovered, however, only the overall shape of the vertical profile matches the true profile. We applied our procedure to spatially resolved maps of mean [Z/H] and [α/Fe] for the Andromeda Galaxy, using an earlier barred dynamical model of M 31. We find that the metallicity is enhanced along the bar, with a possible maxima at the ansae. In the edge-on view, the [Z/H] distribution has an X shape due to the boxy/peanut bulge; the average vertical metallicity gradient is equal to −0.133 ± 0.006 dex kpc⁻¹. We identify a metallicity-enhanced ring around the bar, which also has relatively lower [α/Fe]. The highest [α/Fe] is found in the centre, due to the classical bulge. Away from the centre, the α-overabundance in the bar region increases with height, which could be an indication of a thick disc. We argue that the galaxy assembly resulted in a sharp peak of metallicity in the central few hundred parsecs and a more gentle negative gradient in the remaining disc, but no [α/Fe] gradient. The formation of the bar leads to the re-arrangement of the [Z/H] distribution, causing a flat gradient along the bar. Subsequent star formation close to the bar ends may have produced the metallicity enhancements at the ansae and the [Z/H] enhanced lower-α ring.