HerMES: Halo Occupation Number and Bias Properties of Dusty Galaxies from Angular Clustering Measurements

TL;DR

This study measures the angular clustering of dusty galaxies from Herschel data, using the halo model to estimate their dark matter halo properties and occupation numbers at redshift around 2.

Contribution

It provides new estimates of halo occupation numbers and bias for sub-mm galaxies, linking their clustering to dark matter halo characteristics.

Findings

Sub-mm galaxies with flux >30 mJy reside in halos >5x10^12 M_sun.

Approximately 14% of these galaxies are satellites in larger halos.

Clustering measurements align with models of dark matter distribution.

Abstract

We measure the angular correlation function, w(theta), from 0.5 to 30 arcminutes of detected sources in two wide fields of the Herschel Multi-tiered Extragalactic Survey (HerMES). Our measurements are consistent with the expected clustering shape from a population of sources that trace the dark matter density field, including non-linear clustering at arcminute angular scales arising from multiple sources that occupy the same dark matter halos. By making use of the halo model to connect the spatial clustering of sources to the dark matter halo distribution, we estimate source bias and halo occupation number for dusty sub-mm galaxies at z ~ 2. We find that sub-mm galaxies with 250 micron flux densities above 30 mJy reside in dark matter halos with mass above (5\pm4) x 10^12 M_sun, while (14\pm8)% of such sources appear as satellites in more massive halos.