Dowell, C. Darren and Conley, A. and Glenn, J. and Arumugam, V. and Asboth, V. and Aussel, H. and Bertoldi, F. and Béthermin, M. and Bock, J. and Boselli, A. and Bridge, C. and Buat, V. and Burgarella, D. and Cabrera-Lavers, A. and Casey, C. M. and Chapman, S. C. and Clements, D. L. and Conversi, L. and Cooray, A. and Dannerbauer, H. and De Bernardis, F. and Ellsworth-Bowers, T. P. and Farrah, D. and Franceschini, A. and Griffin, M. and Gurwell, M. A. and Halpern, M. and Hatziminaoglou, E. and Heinis, S. and Ibar, E. and Ivison, R. J. and Laporte, N. and Marchetti, L. and Martínez-Navajas, P. and Marsden, G. and Morrison, G. E. and Nguyen, H. T. and O'Halloran, B. and Oliver, S. J. and Omont, A. and Page, M. J. and Papageorgiou, A. and Pearson, C. P. and Petitpas, G. and Pérez-Fournon, I. and Pohlen, M. and Riechers, D. and Rigopoulou, D. and Roseboom, I. G. and Rowan-Robinson, M. and Sayers, J. and Schulz, B. and Scott, Douglas and Seymour, N. and Shupe, D. L. and Smith, A. J. and Streblyanska, A. and Symeonidis, M. and Vaccari, M. and Valtchanov, I. and Vieira, J. D. and Viero, M. and Wang, L. and Wardlow, J. and Xu, C. K. and Zemcov, M. (2014) HerMES: Candidate High-redshift Galaxies Discovered with Herschel/SPIRE. The Astrophysical Journal, 780 (1). p. 75. ISSN 0004-637X
Abstract
We present a method for selecting z > 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 μm flux densities to search for red sources. We apply this method to 21 deg2 of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e.g., 850 μm) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z > 3. Correcting for the selection completeness and purity, we find that the number of bright (S 500 μm >= 30 mJy), red Herschel sources is 3.3 ± 0.8 deg-2. This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z ~ 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction. . Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.