A millimeter-wave redshift search for the unlensed HyLIRG, HS1700.850.1
Abstract
We report the redshift of an unlensed, highly obscured submillimetre galaxy (SMG), HS1700.850.1, the brightest SMG (S850um =19.1 mJy) detected in the JCMT/SCUBA-2 Baryonic Structure Survey, based on the detection of its CO line emission. Using the IRAM PdBI-WIDEX with 3.6GHz band width, we serendipitously detect an emission line at 150.6 GHz. From a search over 14.5 GHz in the 3-mm and 2-mm atmospheric windows, we confirm the identification of this line as CO(5-4) at z = 2.816, meaning that it does not reside in the z~2.30 proto-cluster in this field. Measurement of the 870um source size (<0.85") from the Sub-Millimeter Array (SMA) confirms a compact emission in a S870um =14.5mJy, LIR~10^13 Lsun component, suggesting an Eddington-limited starburst. We use the double-peaked CO line profile measurements along with the SMA size constraints to study the gas dynamics of a HyLIRG, estimating the gas and dynamical masses of HS1700.850.1. While HS1700.850.1 is one of the most extreme galaxies known in the Universe, we find that it occupies a relative void in the Lyman-Break Galaxy distribution in this field. Comparison with other extreme objects at similar epochs (HyLIRG Quasars), and cosmological simulations, suggests such an anti-bias of bright SMGs could be relatively common, with the brightest SMGs rarely occupying the most overdense regions at z=2-4.
Cite
@article{arxiv.1503.02195,
title = {A millimeter-wave redshift search for the unlensed HyLIRG, HS1700.850.1},
author = {S. C. Chapman and F. Bertoldi and Ian Smail and C. C. Steidel and A. W. Blain and J. E. Geach and M. Gurwell and R. J. Ivison and G. R. Petitpas and N. Reddy},
journal= {arXiv preprint arXiv:1503.02195},
year = {2015}
}
Comments
9 pages, 6 figures, 3 tables, accepted in MNRAS