Herschel/PACS observations of the host galaxy of GRB 031203

Abstract

We present Herschel/PACS observations of the nearby (ζ = 0.1055) dwarf galaxy that has hosted the long gamma-ray burst (LGRB) 031203. Using the PACS data, we have been able to place constraints on the dust temperature, dust mass, total infrared (IR) luminosity and IRderived star formation rate (SFR) for this object. We find that the GRB host galaxy (GRBH) 031203 has a total IR luminosity of 3 × 1010 L⊙ placing it in the regime of the IR-luminous galaxy population. Its dust temperature and specific SFR are comparable to that of many highredshift (ζ = 0.3-2.5) IR-detected GRB hosts (Tdust > 40 K; sSFR > 10 Gyr-1); however, its dust-to-stellar mass ratio is lower than what is commonly seen in IR-luminous galaxies. Our results suggest that GRBH 031203 is undergoing a strong starburst episode and its dust properties are different to those of local dwarf galaxies within the same metallicity and stellar mass range. Furthermore, our measurements place it in a distinct class to the well-studied nearby host of GRB 980425 (ζ = 0.0085), confirming the notion that GRB host galaxies can span a large range in properties even at similar cosmological epochs, making LGRBs an ideal tool in selecting samples of star-forming galaxies up to high redshift. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.