Dust attenuation and dust correction factors at high redshift
Instituto de Astrofísica de Canarias (IAC),
La Laguna, Tenerife,
2 Departamento de Astrofísica, Universidad de La Laguna (ULL), 38205, La Laguna, Tenerife, Spain
3 Asociación ASPID, Apartado de Correos 412, La Laguna, Tenerife, Spain
4 Centro de Estudios de Física del Cosmos de Aragón, Plaza San Juan 1, Planta 2, 44001 Teruel, Spain
5 Herschel Science Centre (ESAC), Villafranca del Castillo, Spain
6 Centro de Astrobiología, INTA-CSIC, PO Box – Apdo. de correos 78, Villanueva de la Cañada Madrid 28691, Spain
7 XMM/Newton Science Operations Centre (ESAC), Villafranca del Castillo, Spain
Received: 14 March 2013
Accepted: 8 April 2013
Lyman-break galaxies (LBGs) represent one of the kinds of star-forming galaxies that are found in the high-redshift universe. The detection of LBGs in the far-infrared (FIR) domain can provide very important clues on their dust attenuation and total star-formation rate (SFR), allowing a more detailed study than has been performed so far. In this work we explore the FIR emission of a sample of 16 LBGs at z ~ 3 in the GOODS-North and GOODS-South fields that are individually detected in PACS-100 μm or PACS-160 μm. These detections demonstrate the possibility of measuring the dust emission of LBGs at high redshift. We find that PACS-detected LBGs at z ~ 3 are highly obscured galaxies which belong to the ultra-luminous or hyper-luminous IR galaxy class. Their total SFR cannot be recovered with the dust attenuation factors obtained from their UV continuum slope or their SED-derived dust attenuation employing Bruzual & Charlot (2003) templates. Both methods underestimate the results for most of the galaxies. Comparing with a sample of PACS-detected LBGs at z ~ 1, we find evidence that the FIR emission of LBGs might have changed with redshift, in the sense that the dustiest LBGs found at z ~ 3 have more prominent FIR emission, are dustier for a given UV slope, and have higher SFR for a given stellar mass than the dustiest LBGs found at z ~ 1.
Key words: galaxies: evolution / galaxies: high-redshift / infrared: galaxies
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Appendix A is available in electronic form at http://www.aanda.org
© ESO, 2013