Herschel/PACS Observations of the Host Galaxy of GRB 031203
  We present Herschel/PACS observations of the nearby (z=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 luminosity and infrared-derived star-formation rate (SFR) for this
object. We find that the GRB host galaxy (GRBH) 031203 has a total infrared
luminosity of 3x10^10 L_sun placing it in the regime of the IR-luminous galaxy
population. Its dust temperature and specific SFR are comparable to that of
many high-redshift (z=0.3-2.5) infrared (IR)-detected GRB hosts (T_dust>40K ;
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 (z=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.
