2012MNRAS.427..703S

We present a pan-chromatic analysis of an unprecedented sample of 1402 250 µm selected galaxies at z < 0.5 (\mi z\mo \mn 0.24) from the Herschel-ATLAS survey. We complement our Herschel 100–500µm data with UV–K-band photometry from the Galaxy And Mass Assembly (GAMA) survey and apply the MAGPHYS energy-balance technique to produce pan-chromatic spectral energy distributions (SEDs) for a representative sample of 250µm selected galaxies spanning the most recent 5 Gyr of cosmic history. We derive estimates of physical parameters, including star formation rates, stellar masses, dust masses and infrared (IR) luminosities. The typical H-ATLAS galaxy at z < 0.5 has a far-infrared luminosity in the range 10¹⁰–10¹²L_☉(SFR: 1–50 M_☉/yr) and thus is broadly representative of normal star-forming galaxies over this redshift range. We show that 250µm selected galaxies contain a larger mass of dust at a given IR luminosity or star formation rate than previous samples selected at 60µm from the IRAS. We derive typical SEDs for H-ATLAS galaxies, and show that the emergent SED shape is most sensitive to specific star formation rate. The optical–UV SEDs also become more reddened due to dust at higher redshifts. Our template SEDs are significantly cooler than existing IR templates. They may therefore be most appropriate for inferring total IR luminosities from moderate redshift sub-millimetre selected samples and for inclusion in models of the lower redshift sub-millimetre galaxy populations.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.