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The impact of dust in host galaxies on quasar luminosity functions
| Title: | The impact of dust in host galaxies on quasar luminosity functions |
| Authors: | Shirakata, Hikari Browse this author | | Okamoto, Takashi Browse this author | | Enoki, Motohiro Browse this author | | Nagashima, Masahiro Browse this author | | Kobayashi, Masakazu A. R. Browse this author | | Ishiyama, Tomoaki Browse this author | | Makiya, Ryu Browse this author |
| Keywords: | galaxies: active | | galaxies: nuclei | | quasars: general |
| Issue Date: | 11-Jun-2015 |
| Publisher: | Oxford University Press |
| Journal Title: | Monthly notices of the royal astronomical society |
| Volume: | 450 |
| Issue: | 1 |
| Start Page: | L6 |
| End Page: | L10 |
| Publisher DOI: | 10.1093/mnrasl/slv035 |
| Abstract: | We have investigated effects of dust attenuation on quasar luminosity functions at z similar to 2 using a semi-analytic galaxy formation model combined with a large cosmological N-body simulation. We estimate the dust attenuation of quasars self-consistently with that of galaxies by considering the dust in their host bulges. We find that the luminosity of the bright quasars is strongly dimmed by the dust attenuation, similar to 2 mag in the B-band. Assuming the empirical bolometric corrections for active galactic nuclei (AGNs) by Marconi et al., we find that this dust attenuation is too strong to explain the B-band and X-ray quasar luminosity functions simultaneously. We consider two possible mechanisms that weaken the dust attenuation. As such a mechanism, we introduce a time delay for AGN activity, that is, gas fuelling to a central black hole starts sometime after the beginning of the starburst induced by a major merger. The other is the anisotropy in the dust distribution. We find that in order to make the dust attenuation of the quasars negligible, either the gas accretion into the black holes has to be delayed at least three times the dynamical time-scale of their host bulges or the dust covering factor is as small as similar to 0.1. |
| Rights: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/59549 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 岡本 崇
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