Core-collapse, superluminous, and gamma-ray burst supernova host galaxy populations at low redshift: the importance of dwarf and starbursting galaxies

Abstract

ABSTRACT We present a comprehensive study of an unbiased sample of 150 nearby (median redshift, z = 0.014) core-collapse supernova (CCSN) host galaxies drawn from the All-Sky Automated Survey for Supernovae (ASAS-SN) for direct comparison to the nearest long-duration gamma-ray burst (LGRB) and superluminous supernova (SLSN) hosts. We use public imaging surveys to gather multiwavelength photometry for all CCSN host galaxies and fit their spectral energy distributions (SEDs) to derive stellar masses and integrated star formation rates (SFRs). CCSNe populate galaxies across a wide range of stellar masses, from blue and compact dwarf galaxies to large spiral galaxies. We find 33$^{+4}_{-4}$ per cent of CCSNe are in dwarf galaxies (M* < 109 M⊙) and 2$^{+2}_{-1}$ per cent are in dwarf starburst galaxies [specific star formation rate (sSFR) > 10−8 yr−1]. We reanalyse low-redshift SLSN and LGRB hosts from the literature (out to z < 0.3) in a homogeneous way and compare against the CCSN host sample. The relative SLSN to CCSN supernova rate is increased in low-mass galaxies and at high sSFRs. These parameters are strongly covariant and we cannot break the degeneracy between them with our current sample, although there is some evidence that both factors may play a role. Larger unbiased samples of CCSNe from projects such as ZTF and LSST will be needed to determine whether host-galaxy mass (a proxy for metallicity) or sSFR (a proxy for star formation intensity and potential IMF variation) is more fundamental in driving the preference for SLSNe and LGRBs in unusual galaxy environments.