Structure of neutral gas: the clue to the formation of massive star explosions

The primary conditions for GRB/SLSN formation are still unknown. A likely hypothesis is that they form in dense and massive super star clusters (SSCs) where the probability of finding very massive stars is high (Schneider et al. 2018; Zhang et al. 2018). Such over-dense regions are known to be more common in post-merger galaxies where the absence of gravitational shear aids gravitational collapse of massive amounts of gas into dense star clusters (Bastian et al. 2008; Elmegreen et al. 2017; Renaud et al. 2018). In some cases dense and massive SSCs are found in the central regions of galaxies where the internal dynamics of the galaxy leads to the assembly of dense molecular clouds (Elmegreen et al. 2009; Gallagher et al. 2018). Investigating this hypothesis requires resolved studies of gas, the fuel of star formation, in the immediate vicinity of GRBs/SLSNe and in their hosts.