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 z 6 and absolute I-band magnitudes -22 > I(AB) > -32 We use the science demonstration observations of the first similar to 16 deg(2) from the Herschel 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, Spitzer, SCUBA and MAMBO. H-ATLAS alone statistically detects the quasars in its survey area at > 5 sigma at 250, 350 and 500 mu 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(AB) > -24 have a comoving star formation rate (derived from 100 mu m rest-frame luminosities) peaking between redshifts of 1 and 2, while high-luminosity quasars with I(AB) -26 have a maximum contribution to the star formation density at z similar to 3. The volume-averaged star formation rate of -22 > IAB > -24 quasars evolves as (1 + z)(2.3 +/- 0.7) at z 2, but the evolution at higher luminosities is much faster reaching (1 + z)(10 +/- 1) at -26 > I(AB) > -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.
|Titolo:||Herschel ATLAS: The cosmic star formation history of quasar host galaxies|
|Autori:||Serjeant S; Bertoldi F; Blain AW; Clements DL; Cooray A; Danese L; Dunlop J; Dunne L; Eales S; Falder J; Hatziminaoglou E; Hughes DH; Ibar E; Jarvis MJ; Lawrence A; Lee MG; Michalowski M; Negrello M; Omont A; Page M; Pearson C; van der Werf PP; White G; Amblard A; Auld R; Baes M; Bonfield DG; Burgarella D; Buttiglione S; Cava A; Dariush A; de Zotti G; Dye S; Frayer D; Fritz J; Gonzalez-Nuevo J; Herranz D; Ivison RJ; Lagache G; Leeuw L; Lopez-Caniego M; Maddox S; Pascale E; Pohlen M; Rigby E; Rodighiero G; Samui S; Sibthorpe B; Smith DJB; Temi P; Thompson M; Valtchanov I; Verma A|
|Data di pubblicazione:||2010|
|Digital Object Identifier (DOI):||10.1051/0004-6361/201014565|
|Appare nelle tipologie:||1.1 Journal article|