The influence of wavelength, flux, and lensing selection effects on the redshift distribution of dusty, star-forming galaxies

• Published in: Astronomy & Astrophysics
• Main Authors: Béthermin, Matthieu, de Breuck, Carlos, Sargent, Mark, Daddi, Emanuele
• Other Authors: European Southern Observatory (ESO), Astronomy Centre, University of Sussex, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ANR-08-JCJC-0008,UPGAL(2008), European Project: 240039,EC:FP7:ERC,ERC-2009-StG,UPGAL(2009)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: submillimeter: galaxies; infrared: galaxies; galaxies: evolution; galaxies: high-redshift; galaxies: star formation; gravitational lensing: strong; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; South Pole; South pole
• Online Access: https://cea.hal.science/cea-01300543; https://cea.hal.science/cea-01300543/document; https://cea.hal.science/cea-01300543/file/aa25718-15.pdf; https://doi.org/10.1051/0004-6361/201525718

International audience We interpret the wide variety of redshift distributions for galaxies found by far-infrared and (sub) millimeter deep surveys depending on their depth and wavelength using our phenomenological model of galaxy evolution. This model reproduces the observed redshift distributions from 100 μm to 1.4 mm and, especially, the increase in the median redshift with survey wavelength without any new parameter tuning. This median redshift also varies significantly with the depth of the surveys, and deeper surveys do not necessarily probe higher redshifts. Paradoxically, at a fixed wavelength and flux limit, the lensed sources are not always at higher redshift. We found that the higher redshift of 1.4 mm-selected South Pole Telescope (SPT) sources compared to other SMG surveys is caused not only by the lensing selection, but also by the longer wavelength. This SPT sample is expected to be dominated by a population of lensed main-sequence galaxies and a minor contribution (~10%) of unlensed extreme starbursts.