Deep Herschel view of obscured star formation in the Bullet cluster

We use deep, five band (100-500 mu m) data from the Herschel Lensing Survey (HLS) to fully constrain the obscured star formation rate, SFRFIR, of galaxies in the Bullet cluster (z = 0.296), and a smaller background system (z = 0.35) in the same field. Herschel detects 23 Bullet cluster members with a total SFRFIR = 144 +/- 14 M-circle dot yr(-1). On average, the background system contains brighter far-infrared (FIR) galaxies, with similar to 50% higher SFRFIR (21 galaxies; 207 +/- 9 M-circle dot yr(-1)). SFRs extrapolated from 24 mu m flux via recent templates (SFR24 mu m) agree well with SFRFIR for similar to 60% of the cluster galaxies. In the remaining similar to 40%, SFR24 mu m underestimates SFRFIR due to a significant excess in observed S-100/S-24 (rest frame S-75/S-18) compared to templates of the same FIR luminosity.