2010/05/13 by S. Serjeant, F. Bertoldi, A. W. Blain +50
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Photometry (optics) #Quasar #Redshift #Sky #Star formation #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201014565
Accepted by Astronomy and Astrophysics, Herschel special issue
arxiv created 2010/05/13 · openalex publication_date 2010/07/01 · arxiv updated 2015/05/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a derivation of the star formation rate per comoving volume of quasar host galaxies, derived from stacking analyses of far-infrared to mm-wave photometry of quasars with redshifts 0 < <i>z<i/> < 6 and absolute <i>I<i/>-band magnitudes -22 > <i>I<i/><sub>AB<sub/> > -32 We use the science demonstration observations of the first ~16 deg<sup>2<sup/> from the <i>Herschel<i/> Astrophysical Terahertz Large Area Survey (H-ATLAS) in which there are 240 quasars from the Sloan Digital Sky Survey (SDSS) and a further 171 from the 2dF-SDSS LRG and QSO (2SLAQ) survey. We supplement this data with a compilation of data from IRAS, ISO, <i>Spitzer<i/>, SCUBA and MAMBO. H-ATLAS alone statistically detects the quasars in its survey area at >5<i>σ<i/> at 250,350 and 500 <i>μ<i/>m. From the compilation as a whole we find striking evidence of downsizing in quasar host galaxy formation: low-luminosity quasars with absolute magnitudes in the range -22 > <i>I<i/><sub>AB<sub/> > -24 have a comoving star formation rate (derived from 100 <i>μ<i/>m rest-frame luminosities) peaking between redshifts of <i>1<i/> and <i>2<i/>, while high-luminosity quasars with <i>I<i/><sub>AB<sub/> < -26 have a maximum contribution to the star formation density at <i>z<i/> ~ 3. The volume-averaged star formation rate of -22 > <i>I<i/><sub>AB<sub/> > -24 quasars evolves as (1 + <i>z<i/>)<sup>2.3±0.7<sup/> at <i>z<i/> < 2, but the evolution at higher luminosities is much faster reaching (1 + <i>z<i/>)<sup>10±1<sup/> at -26 > <i>I<i/><sub>AB<sub/> > -28. We tentatively interpret this as a combination of a declining major merger rate with time and gas consumption reducing fuel for both black hole accretion and star formation.