The Herschel-PEP survey: evidence for downsizing in the hosts of dusty star-forming systems

Abstract

By making use of Herschel-PEP observations of the COSMOS and Extended Groth Strip fields, we have estimated the dependence of the clustering properties of FIR-selected sources on their 100um fluxes. Our analysis shows a tendency for the clustering strength to decrease with limiting fluxes: r0(S100um >8 mJy)~4.3 Mpc and r0(S100um >5 mJy)~5.8 Mpc. These values convert into minimum halo masses Mmin~10^{11.6} Msun for sources brighter than 8 mJy and Mmin~10^{12.4} Msun for S100um > 5 mJy galaxies. We show such an increase of the clustering strength to be due to an intervening population of z~2 sources, which are very strongly clustered and whose relative contribution, equal to about 10% of the total counts at S100um > 2 mJy, rapidly decreases for brighter flux cuts. By removing such a contribution, we find that z <~ 1 FIR galaxies have approximately the same clustering properties, irrespective of their flux level. The above results were then used to investigate the intrinsic dependence on cosmic epoch of the clustering strength of dusty star-forming galaxies between z~0 and z~2.5. In order to remove any bias in the selection process, the adopted sample only includes galaxies observed at the same rest-frame wavelength, lambda~60 um, which have comparable luminosities and therefore star-formation rates (SFR>~100 Msun/yr). Our analysis shows that the same amount of (intense) star forming activity takes place in extremely different environments at the different cosmological epochs. For z<~1 the hosts of such star forming systems are small, Mmin~10^{11} Msun, isolated galaxies. High (z~2) redshift star formation instead seems to uniquely take place in extremely massive/cluster-like halos, Mmin~10^{13.5} Msun, which are associated with the highest peaks of the density fluctuation field at those epochs. (abridged)

12 pages, 8 figures, to appear in MNRAS

References in corpus (12)

• Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey
• The LABOCA Survey of the Extended Chandra Deep Field South: Clustering of submillimetre galaxies
• GOODS-Herschel and CANDELS: The Morphologies of Ultraluminous Infrared Galaxies at z~2
• Clustering properties of BzK-selected galaxies in GOODS-N: environmental quenching and triggering of star formation at z ~ 2
• Clustering properties of galaxies selected in stellar mass: Breaking down the link between luminous and dark matter in massive galaxies from z=0 to z=2
• The evolution of galaxy clustering since z = 3 using the UKIDSS Ultra Deep Survey: the divergence of passive and star-forming galaxies
• The discovery of a significant sample of massive galaxies at redshifts 5 < z < 6 in the UKIDSS Ultra Deep Survey Early Data Release
• A highly obscured and strongly clustered galaxy population discovered with the Spitzer Space Telescope
• On the evolution of clustering of 24um-selected galaxies
• Clustering Properties of restframe UV selected galaxies II: Migration of Star Formation sites with cosmic time from GALEX and CFHTLS
• Clustering of star-forming galaxies detected in mid-infrared with the Spitzer wide-area survey
• Herschel-ATLAS/GAMA: spatial clustering of low-redshift sub-mm galaxies

Cited by in corpus (15)

• The SCUBA-2 Cosmology Legacy Survey: The clustering of submillimetre galaxies in the UKIDSS UDS field
• Far-infrared surveys of galaxy evolution
• The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field
• The clustering properties of radio-selected AGN and star-forming galaxies up to redshifts z~3
• Overdensities of Submillimetre-Bright Sources around Candidate Protocluster Cores Selected from the South Pole Telescope Survey
• Large scale clustering measurements with photometric redshifts: comparing the dark matter halos of X-ray AGN, star-forming and passive galaxies at z~1
• Rapid build-up of the stellar content in the protocluster core SPT2349$-$56 at $z=4.3$
• The evolution of galaxy star formation activity in massive halos
• SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES) IV: Spatial clustering and halo masses of 450-$\mu$m-selected sub-millimeter galaxies
• Characterising the signatures of star-forming galaxies in the extra-galactic $\gamma$-ray background
• The study of the angular and spatial distribution of radio selected AGNs and star-forming galaxies in the ELAIS N1 field
• Downsizing of Star Formation Measured from the Clustered Infrared Background Correlated with Quasars
• A study on the Clustering Properties of Radio-Selected sources in the Lockman Hole Region at 325 MHz
• Modeling submillimeter galaxies in cosmological simulations: Contribution to the cosmic star formation density and predictions for future surveys
• Hosts and environments: a (large-scale) radio history of AGN and star-forming galaxies