The Herschel census of infrared SEDs through cosmic time

M. Symeonidis, M. Vaccari, S. Berta, M. J. Page, D. Lutz, V. Arumugam, H. Aussel, J. Bock, A. Boselli, V. Buat, P. L. Capak, D. L. Clements, A. Conley, L. Conversi, A. Cooray, C. D. Dowell, D. Farrah, A. Franceschini, E. Giovannoli, J. Glenn, M. Griffin, E. Hatziminaoglou, H.-S. Hwang, E. Ibar, O. Ilbert, R. J. Ivison, E.~L. Floc'h, S. Lilly, J. S. Kartaltepe, B. Magnelli, G. Magdis, L. Marchetti, H. T. Nguyen, R. Nordon, B. O'Halloran, S. J. Oliver, A. Omont, A. Papageorgiou, H. Patel, C. P. Pearson, I. Pérez-Fournon, M. Pohlen, P. Popesso, F. Pozzi, D. Rigopoulou, L. Riguccini, D. Rosario, I. G. Roseboom, M. Rowan-Robinson, M. Salvato, B. Schulz, D. Scott, N. Seymour, D. L. Shupe, A. J. Smith, I. Valtchanov, L. Wang, C. K. Xu, M. Zemcov, S. Wuyts

OAI: oai:purehost.bath.ac.uk:openaire_cris_publications/e22c070e-2502-4dc0-a6d3-f09ca00a09d3 • DOI: https://doi.org/10.1093/mnras/stt330

Using Herschel data from the deepest SPIRE and PACS surveys (HerMES and PEP) in COSMOS, GOODS-S and GOODS-N, we examine the dust properties of infrared (IR)-luminous (LIR > 1010 L⊙) galaxies at 0.1 < z < 2 and determine how these evolve with cosmic time. The unique angle of this work is the rigorous analysis of survey selection effects, making this the first study of the star-formation-dominated, IR-luminous population within a framework almost entirely free of selection biases. We find that IR-luminous galaxies have spectral energy distributions (SEDs) with broad far-IR peaks characterized by cool/extended dust emission and average dust temperatures in the 25–45 K range. Hot (T > 45 K) SEDs and cold (T < 25 K), cirrus-dominated SEDs are rare, with most sources being within the range occupied by warm starbursts such as M82 and cool spirals such as M51. We observe a luminosity–temperature (L-T) relation, where the average dust temperature of log [LIR/L⊙] ∼ 12.5 galaxies is about 10 K higher than that of their log [LIR/L⊙] ∼ 10.5 counterparts. However, although the increased dust heating in more luminous systems is the driving factor behind the L-T relation, the increase in dust mass and/or starburst size with luminosity plays a dominant role in shaping it. Our results show that the dust conditions in IR-luminous sources evolve with cosmic time: at high redshift, dust temperatures are on average up to 10 K lower than what is measured locally (z ≲ 0.1). This is manifested as a flattening of the L-T relation, suggesting that (ultra)luminous infrared galaxies [(U)LIRGs] in the early Universe are typically characterized by a more extended dust distribution and/or higher dust masses than local equivalent sources. Interestingly, the evolution in dust temperature is luminosity dependent, with the fraction of LIRGs with T < 35 K showing a two-fold increase from z ∼ 0 to z ∼ 2, whereas that of ULIRGs with T < 35 K shows a six-fold increase. Our results suggest a greater diversity in the IR-luminous population at high redshift, particularly for ULIRGs

galaxies: evolution galaxies: high redshift galaxies: starburst infrared: galaxies submillimetre: galaxies