The host galaxies of core-collapse supernovae and gamma-ray bursts

Abstract

We present a comparative study of the galactic and small‐scale environments of gamma‐ray bursts (GRBs) and core‐collapse supernovae (CCSNe). We use a sample of 34 GRB hosts at z < 1.2, and a comparison sample of 58 supernova hosts located within the Great Observatories Origins Deep Survey footprint. We fit template spectra to the available photometric data, which span the range 0.45–24 μm, and extract absolute magnitudes, stellar masses and star formation rates from the resulting fits. Our results broadly corroborate previous findings, but offer significant enhancements in spectral coverage and a factor 2–3 increase in sample size. Specifically, we find that CCSNe occur frequently in massive spirals (spiral fraction ∼50 per cent). In contrast GRBs occur in small, relatively low mass galaxies with high specific and surface star formation rates, and have a spiral fraction of only ∼10 per cent. A comparison of the rest‐frame absolute magnitudes of the GRB and CCSN sample is less conclusive than found in previous work, suggesting that while GRB hosts are typically both smaller and bluer than those of CCSN their total blue light luminosities are only slightly lower. We suggest this is likely due to rapid periods of intensified star formation activity, as indicated by the high specific SFRs, which both create the GRB progenitors and briefly significantly enhance the host galaxy blue luminosity. Finally, our analysis of local environments of GRBs and CCSNe shows that GRBs are highly concentrated on their host light, and further occur in regions of higher absolute surface luminosity than CCSNe.

GRB 080517: a local, low-luminosity gamma-ray burst in a dusty galaxy at z = 0.09

“…Long-duration GRBs are typically associated with the peak light in their host galaxies, and with recent star formation (e.g Svensson et al 2010). However, the broadband continuum emission of the host of GRB 080517 is dominated by a much older stellar population.…”

“…A number of studies now constrain the stellar properties of typical GRB hosts (e.g. Savaglio, Glazebrook, & LeBorgne 2009;Svensson et al 2010;Hjorth et al 2012), their radio properties (e.g. Micha lowski et al 2012;Stanway, Davies, & Levan 2010;Stanway, Levan, & Davies 2014;Perley et al 2014) and behaviour in the far-infrared (Hunt et al 2014;Symeonidis et al 2014).…”

The Galactic dust-to-metals ratio and metallicity using gamma-ray bursts

“…Those objects are typically relatively high mass, evolved systems. Zafar et al (2011) showed in an analysis of GRB afterglows that GRB host galaxies, which are typically young and star-forming with low metallicities and hard radiation environments (Christensen et al 2004;Castro Cerón et al 2006;Savaglio et al 2009;Svensson et al 2010;Chary et al 2002;Fynbo et al 2008;Watson et al 2010), have substantially lower dust-to-gas ratios than the local group even after accounting for metallicity.…”

The First Billion Years project: gamma-ray bursts at z > 5

“…This underlying excess has been explained for many different reasons ranging from observational biases (Coward et al 2008;Elliott et al 2012) to redshift-dependent initial mass functions (IMF; Wang & Dai 2011). However, the most favoured explanation is a metallicity dependence that is driven by (i) the requirement of the single progenitor collapsar model, and (ii) LGRB host galaxy observations (see, e.g., Le Floc'h et al 2003;Savaglio, Glazebrook & Le Borgne 2009;Svensson et al 2010;Mannucci, Salvaterra & Campisi 2011).…”