AEGIS: new evidence linking active galactic nuclei to the quenching of star formation
Abstract
Using Chandra X-ray observations in the All-Wavelength Extended Groth Strip International Survey (AEGIS) we identify 241 X-ray-selected active galactic nuclei (AGNs; L2–10 > 10^42 ergs s^−1) and study the properties of their host galaxies in the range 0.4 < z < 1.4. By making use of infrared photometry from the Palomar Observatory and BRI imaging from the Canada-France-Hawaii Telescope, we estimate AGN host galaxy stellar masses and show that both stellar mass and photometric redshift estimates (where necessary) are robust to the possible contamination from AGNs in our X-ray-selected sample. Accounting for the photometric and X-ray sensitivity limits of the survey, we construct the stellar mass function of X-ray-selected AGN host galaxies and find that their abundance decreases by a factor of ~2 since z ~ 1 but remains roughly flat as a function of stellar mass. We compare the abundance of AGN hosts to the rate of star formation quenching observed in the total galaxy population. If the timescale for X-ray-detectable AGN activity is roughly 0.5-1 Gyr, as suggested by black hole demographics and recent simulations, then we deduce that the inferred AGN "trigger" rate matches the star formation quenching rate, suggesting a link between these phenomena. However, given the large range of nuclear accretion rates we infer for the most massive and red hosts, X-ray-selected AGNs may not be directly responsible for quenching star formation.
Additional Information
© 2008 The American Astronomical Society. Received 2007 October 10; accepted 2008 March 26. We would like to thank Ray Carlberg for useful discussions on this project. K. B. would like to acknowledge support from Olivier Le Fèvre and the Observatoire Astronomique de Marseille Provence, where he was a visiting researcher. The Palomar Survey was supported by National Science Foundation grant AST 03-07859 and NASA STScI grant HST-AR-09920.01-A. Support from NSF grants 00-71198 to the University of California, Santa Cruz, and AST 00-71048 to the University of California, Berkeley, is also gratefully acknowledged. Financial support has also been provided through PPARC and the Marie Curie Fellowship grant MEIF-CT-2005-025108 (A. G.), the Leverhulme trust (K. N.), the Hubble Fellowship grants HF-01165.01-A (J. A. N.) and HF-01182.01-A (A. L. C.), and the STFC (E. L.). We wish to recognize and acknowledge the highly significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. It is a privilege to be given the opportunity to conduct observations from this mountain.Attached Files
Published - BUNapj08.pdf
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Additional details
- Eprint ID
- 13835
- Resolver ID
- CaltechAUTHORS:BUNapj08
- AST 03-07859
- NSF
- HST-AR-09920.01-A
- NASA
- AST 00-71198
- NSF
- AST 00-71048
- NSF
- Particle Physics and Astronomy Research Council (PPARC)
- MEIF-CT-2005-025108
- Marie Curie Fellowship
- Leverhulme Trust
- HF-01165.01-A
- NASA Hubble Fellowship
- HF-01182.01-A
- NASA Hubble Fellowship
- Created
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2009-04-03Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field