skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION

Abstract

We reason that without physical fine-tuning, neither the supermassive black holes (SMBHs) nor the stellar bulges can self-regulate or inter-regulate by driving away already fallen cold gas to produce the observed correlation between them. We suggest an alternative scenario where the observed mass ratios of the SMBHs to bulges reflect the angular momentum distribution of infallen gas such that the mass reaching the stable accretion disk is a small fraction of that reaching the bulge region, averaged over the cosmological timescales. We test this scenario using high-resolution, large-scale cosmological hydrodynamic simulations, without active galactic nucleus (AGN) feedback, assuming the angular momentum distribution of gas landing in the bulge region yields a Mestel disk that is supported by independent simulations resolving the Bondi radii of SMBHs. A mass ratio of 0.1%–0.3% between the very low angular momentum gas that free falls to the subparsec region to accrete to the SMBH and the overall star formation rate is found. This ratio is found to increase with increasing redshift to within a factor of ∼2, suggesting that the SMBH-to-bulge ratio is nearly redshift independent, with a modest increase with redshift, which is a testable prediction. Furthermore, the duty cycle of AGNs with highmore » Eddington ratios is expected to increase significantly with redshift. Finally, while SMBHs and bulges are found to coevolve on ∼30–150 Myr timescales or longer, there is indication that on still smaller timescales, the SMBH accretion and star formation may be less correlated.« less

Authors:
 [1]
  1. Princeton University Observatory, Princeton, NJ 08544 (United States)
Publication Date:
OSTI Identifier:
22518971
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 805; Journal Issue: 1; 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; BLACK HOLES; COMPUTERIZED SIMULATION; CORRELATIONS; COSMOLOGY; GALAXIES; GALAXY NUCLEI; HYDRODYNAMICS; MASS; QUASARS; RED SHIFT; STAR EVOLUTION; STARS

Citation Formats

Cen, Renyue, E-mail: cen@astro.princeton.edu. COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION. United States: N. p., 2015. Web. doi:10.1088/2041-8205/805/1/L9.
Cen, Renyue, E-mail: cen@astro.princeton.edu. COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION. United States. doi:10.1088/2041-8205/805/1/L9.
Cen, Renyue, E-mail: cen@astro.princeton.edu. Wed . "COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION". United States. doi:10.1088/2041-8205/805/1/L9.
@article{osti_22518971,
title = {COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION},
author = {Cen, Renyue, E-mail: cen@astro.princeton.edu},
abstractNote = {We reason that without physical fine-tuning, neither the supermassive black holes (SMBHs) nor the stellar bulges can self-regulate or inter-regulate by driving away already fallen cold gas to produce the observed correlation between them. We suggest an alternative scenario where the observed mass ratios of the SMBHs to bulges reflect the angular momentum distribution of infallen gas such that the mass reaching the stable accretion disk is a small fraction of that reaching the bulge region, averaged over the cosmological timescales. We test this scenario using high-resolution, large-scale cosmological hydrodynamic simulations, without active galactic nucleus (AGN) feedback, assuming the angular momentum distribution of gas landing in the bulge region yields a Mestel disk that is supported by independent simulations resolving the Bondi radii of SMBHs. A mass ratio of 0.1%–0.3% between the very low angular momentum gas that free falls to the subparsec region to accrete to the SMBH and the overall star formation rate is found. This ratio is found to increase with increasing redshift to within a factor of ∼2, suggesting that the SMBH-to-bulge ratio is nearly redshift independent, with a modest increase with redshift, which is a testable prediction. Furthermore, the duty cycle of AGNs with high Eddington ratios is expected to increase significantly with redshift. Finally, while SMBHs and bulges are found to coevolve on ∼30–150 Myr timescales or longer, there is indication that on still smaller timescales, the SMBH accretion and star formation may be less correlated.},
doi = {10.1088/2041-8205/805/1/L9},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 805,
place = {United States},
year = {2015},
month = {5}
}