Herschel ATLAS: The cosmic star formation history of quasar host galaxies
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 > −32 We use the science demonstration observati...
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2010 |
| Country: | México |
| Institution: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repository: | Repositorio Institucional del INAOE |
| Language: | English |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1504 |
| Online Access: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1504 |
| Access Level: | Open access |
| Keyword: | info:eu-repo/classification/Inspec/Galaxies: active info:eu-repo/classification/Inspec/Infrared: galaxies info:eu-repo/classification/Inspec/Quasars: general info:eu-repo/classification/Inspec/Galaxies: formation info:eu-repo/classification/Inspec/Submillimeter: galaxies info:eu-repo/classification/Inspec/Galaxies: starburst info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Summary: | 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 > −32 We use the science demonstration observations of the first ∼ 16 deg² 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 área at > 5σ at 250, 350 and 500 μm. 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 > −24 have a comoving star formation rate (derived from 100 μm rest-frame luminosities) peaking between redshifts of 1 and 2, while high-luminosity quasars with I < −26 have a maximum contribution to the star formation density at z ∼ 3. The volume-averaged star formation rate of −22 > I > −24 quasars evolves as (1 + z)²̇³⁺⁻⁰̇⁷ at z < 2, but the evolution at higher luminosities is much faster reaching (1 + z) ¹⁰⁺⁻¹at −26 > I > −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. |
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