Simpson, J.M. and Swinbank, A.M. and Smail, I. and Alexander, D.M. and Brandt, W.N. and Bertoldi, F. and Chapman, S.C. and Coppin, K.E.K. and Danielson, A.L.R. and Dannerbauer, H. and De Breuck, C. and Da Cunha, E. and Greve, T.R. and Hodge, J.A. and Ivison, R.J. and Karim, A. and Knudsen, K.K. and Poggianti, B.M. and Thomson, A.P. and Schinnerer, E. and Walter, F. and Wardlow, J.L. and Weiss, A. and van der Werf, P.P. (2014) 'An ALMA survey of submillimeter galaxies in the Extended Chandra Deep Field South : the redshift distribution and evolution of submillimeter galaxies.', Astrophysical journal., 788 (2). p. 125.
We present the first photometric redshift distribution for a large sample of 870 μm submillimeter galaxies (SMGs) with robust identifications based on observations with ALMA. In our analysis we consider 96 SMGs in the Extended Chandra Deep Field South, 77 of which have 4-19 band photometry. We model the SEDs for these 77 SMGs, deriving a median photometric redshift of z phot = 2.3 ± 0.1. The remaining 19 SMGs have insufficient photometry to derive photometric redshifts, but a stacking analysis of Herschel observations confirms they are not spurious. Assuming that these SMGs have an absolute H-band magnitude distribution comparable to that of a complete sample of z ~ 1-2 SMGs, we demonstrate that they lie at slightly higher redshifts, raising the median redshift for SMGs to z phot = 2.5 ± 0.2. Critically we show that the proportion of galaxies undergoing an SMG-like phase at z ≥ 3 is at most 35% ± 5% of the total population. We derive a median stellar mass of M sstarf = (8 ± 1) × 1010 M ☉, although there are systematic uncertainties of up to 5 × for individual sources. Assuming that the star formation activity in SMGs has a timescale of ~100 Myr, we show that their descendants at z ~ 0 would have a space density and MH distribution that are in good agreement with those of local ellipticals. In addition, the inferred mass-weighted ages of the local ellipticals broadly agree with the look-back times of the SMG events. Taken together, these results are consistent with a simple model that identifies SMGs as events that form most of the stars seen in the majority of luminous elliptical galaxies at the present day.
|Keywords:||Galaxies: evolution, Galaxies, High-redshift, Galaxies: starburst.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.1088/0004-637X/788/2/125|
|Publisher statement:||© 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A.|
|Date accepted:||16 April 2014|
|Date deposited:||07 August 2014|
|Date of first online publication:||30 May 2014|
|Date first made open access:||No date available|
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