The impact of dust in host galaxies on quasar luminosity functions

• Shirakata, Hikari

• Okamoto, Takashi

• Enoki, Motohiro

• Nagashima, Masahiro

• Kobayashi, Masakazu A. R.

• Ishiyama, Tomoaki

• Makiya, Ryu

抄録

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.

収録刊行物

• Monthly notices of the royal astronomical society

  Monthly notices of the royal astronomical society 450 (1), L6-L10, 2015-06-11

  Oxford University Press

キーワード

• galaxies: active
• galaxies: nuclei
• quasars: general

詳細情報

• CRID: 1050282813994955520
• NII論文ID: 120005624081
• ISSN: 13652966
• ISSN: 00358711
• HANDLE: 2115/59549
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles