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Title: BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING

Abstract

We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

Authors:
;  [1]
  1. Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)
Publication Date:
OSTI Identifier:
22215374
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 777; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; ANGULAR MOMENTUM; ANNIHILATION; BLACK HOLES; COMPUTERIZED SIMULATION; DENSITY; FEEDBACK; GALAXIES; NONLUMINOUS MATTER; QUASARS; STARS

Citation Formats

Dehnen, Walter, and King, Andrew. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING. United States: N. p., 2013. Web. doi:10.1088/2041-8205/777/2/L28.
Dehnen, Walter, & King, Andrew. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING. United States. https://doi.org/10.1088/2041-8205/777/2/L28
Dehnen, Walter, and King, Andrew. 2013. "BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING". United States. https://doi.org/10.1088/2041-8205/777/2/L28.
@article{osti_22215374,
title = {BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING},
author = {Dehnen, Walter and King, Andrew},
abstractNote = {We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.},
doi = {10.1088/2041-8205/777/2/L28},
url = {https://www.osti.gov/biblio/22215374}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 777,
place = {United States},
year = {Sun Nov 10 00:00:00 EST 2013},
month = {Sun Nov 10 00:00:00 EST 2013}
}