Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive 

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-54772

Bournaud, F; Dekel, A; Teyssier, R; Cacciato, M; Daddi, E; Juneau, S; Shankar, F (2011). Black hole growth and active galactic nuclei obscuration by instability-driven inflows in high-redshift disk galaxies fed by cold streams. Astrophysical Journal Letters, 741(2):L33.

[img]
Preview
Accepted Version
PDF (Version 3)
336Kb
[img]
Preview
Accepted Version
PDF (Version 2)
333Kb
[img]
Preview
Accepted Version
PDF (Version 1)
332Kb

Abstract

Disk galaxies at high redshift have been predicted to maintain high gas surface densities due to continuous feeding by intense cold streams leading to violent gravitational instability, transient features, and giant clumps. Gravitational torques between the perturbations drive angular momentum out and mass in, and the inflow provides the energy for keeping strong turbulence. We use analytic estimates of the inflow for a self-regulated unstable disk at a Toomre stability parameter Q ~ 1, and isolated galaxy simulations capable of resolving the nuclear inflow down to the central parsec. We predict an average inflow rate ~10 M sun yr-1 through the disk of a 1011 M sun galaxy, with conditions representative of z ~ 2 stream-fed disks. The inflow rate scales with disk mass and (1 + z)3/2. It includes clump migration and inflow of the smoother component, valid even if clumps disrupt. This inflow grows the bulge, while only a fraction of >~ 10-3 of it needs to accrete onto a central black hole (BH), in order to obey the observed BH-bulge relation. A galaxy of 1011 M sun at z ~ 2 is expected to host a BH of ~108 M sun, accreting on average with moderate sub-Eddington luminosity L X ~ 1042-1043 erg s-1, accompanied by brighter episodes when dense clumps coalesce. We note that in rare massive galaxies at z ~ 6, the same process may feed ~109 M sun BH at the Eddington rate. High central gas column densities can severely obscure active galactic nuclei in high-redshift disks, possibly hindering their detection in deep X-ray surveys.

Other titles:Black Hole growth and AGN obscuration by instability-driven inflows in high-redshift disk galaxies fed by cold streams
Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Theoretical Physics
DDC:530 Physics
Language:English
Date:November 2011
Deposited On:18 Feb 2012 14:23
Last Modified:19 Apr 2014 21:28
Publisher:Institute of Physics Publishing
ISSN:0004-637X (P) 1538-4357 (E)
Publisher DOI:10.1088/2041-8205/741/2/L33
Related URLs:http://arxiv.org/abs/1107.1483
Citations:Web of Science®. Times Cited: 48
Google Scholar™

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page