Faint Submillimeter Galaxies identified through their optical/near-infrared colours I: spatial clustering and halo masses

Autor: Chen, Chian-Chou, Smail, Ian, Swinbank, A. M., Simpson, James M., Almaini, Omar, Conselice, Christopher J., Hartley, Will G., Mortlock, Alice, Simpson, Chris, Wilkinson, Aaron
Rok vydání: 2016
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/0004-637X/831/1/91
Popis: The properties of submillimeter galaxies (SMGs) that are fainter than the confusion limit of blank-field single-dish surveys ($S_{850} \lesssim$ 2 mJy) are poorly constrained. Using a newly developed color selection technique, Optical-Infrared Triple Color (OIRTC), that has been shown to successfully {select} such faint SMGs, we identify a sample of 2938 OIRTC-selected galaxies, dubbed Triple Color Galaxies (TCGs), in the UKIDSS-UDS field. We show that these galaxies have a median 850 $\mu$m flux of S$_{850} = 0.96\pm0.04$ mJy (equivalent to a star-formation rate SFR $\sim60-100$ M$_\odot$ yr$^{-1}$ based on SED fitting), representing the first large sample of faint SMGs that bridges the gap between bright SMGs and normal star-forming galaxies in S$_{850}$ and $L_{\rm IR}$. We assess the basic properties of TCGs and their relationship with other galaxy populations at $z\sim2$. We measure the two-point autocorrelation function for this population and derive a typical halo mass of log$_{10}$(M$_{\rm halo}$) $=12.9^{+0.2}_{-0.3}$, $12.7^{+0.1}_{-0.2}$, and $12.9^{+0.2}_{-0.3}$ $h^{-1}$M$_\odot$ at $z=1-2$, $2-3$, and $3-5$, respectively. Together with the bright SMGs (S$_{850} \gtrsim 2$ mJy) and a comparison sample of less far-infrared luminous star-forming galaxies, we find a lack of dependence between spatial clustering and S$_{850}$ (or SFR), suggesting that the difference between these populations may lie in their local galactic environment. Lastly, on the scale of $\sim8-17$ kpc at $1Comment: ApJ in press, 13 pages, 11 figures
Databáze: arXiv