Local supermassive black holes, relics of active galactic nuclei and the X-ray background

Clicks: 2
ID: 298483
2004
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #621 of 913 articles by views in monthly notices of the royal astronomical society

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 913 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
We quantify the importance of mass accretion during active galactic nuclei (AGN) phases in the growth of supermassive black holes (BHs) by comparing the mass function of black holes in the Local Universe with that expected from AGN relics, which are black holes grown entirely with mass accretion during AGN phases. The local BH mass function (BHMF) is estimated by applying the well-known correlations between BH mass, bulge luminosity and stellar velocity dispersion to galaxy luminosity and velocity functions. We find that different correlations provide the same BHMF only if they have the same intrinsic dispersion. The density of supermassive black holes in the Local Universe that we estimate is ρBH= 4.6+1.9−1.4h20.7× 105 M⊙ Mpc−3. The relic BHMF is derived from the continuity equation with the only assumption that AGN activity is due to accretion on to massive BHs and that merging is not important. We find that the relic BHMF at z= 0 is generated mainly at z < 3 where the major part of the growth of a BH takes place. Moreover, BH growth is antihierarchical in the sense that smaller BHs (MBH < 107 M⊙) grow at lower redshifts (z < 1) with respect to more massive ones (z∼ 1–3). Unlike previous work, we find that the BHMF of AGN relics is perfectly consistent with the local BHMF, indicating that local BHs were mainly grown during AGN activity. This agreement is obtained while satisfying, at the same time, the constraints imposed from the X-ray background (XRB). The comparison between the local and relic BHMFs also suggests that the merging process is not important in shaping the relic BHMF, at least at low redshifts (z < 3), and allows us to estimate the average radiative efficiency (ɛ), the ratio between emitted and Eddington luminosity (λ) and the average lifetime of active BHs. Our analysis thus suggests the following scenario: local BHs grew during AGN phases in which accreting matter was converted into radiation with efficiencies ɛ= 0.04–0.16 and emitted at a fraction λ= 0.1–1.7 of the Eddington luminosity. The average total lifetime of these active phases ranges from ≃ 4.5 × 108 yr for MBH < 108 M⊙ to ≃ 1.5 × 108 yr for MBH > 109 M⊙, but can become as large as ∼109 yr for the lowest acceptable ɛ and λ values.
Reference Key
openalex_W3099428329 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors A. Marconi, G. Risaliti, R. Gilli, L. K. Hunt, R. Maiolino, M. Salvati
Journal monthly notices of the royal astronomical society
Year 2004
DOI
10.1111/j.1365-2966.2004.07765.x
URL
https://doi.org/10.1111/j.1365-2966.2004.07765.x
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.