Black Hole Growth Is Mainly Linked to Host-galaxy Stellar Mass Rather Than Star Formation Rate

Yang, G.; Chen, C.-T.J.; Vito, F.; Brandt, W.N.; Alexander, D.M.; Luo, B.; Sun, M.Y.; Xue, Y.Q.; Bauer, F.E.; Koekemoer, A.M.; Lehmer, B.D.; Liu, T.; Schneider, D.P.; Shemmer, O.; Trump, J.R.; Vignali, C.; Wang, J.-X.

Abstract

We investigate the dependence of black-hole accretion rate (BHAR) on host-galaxy star formation rate (SFR) and stellar mass (M∗) in the CANDELS/GOODS-South field in the redshift range of 0.5≤z<2.0. Our sample consists of ≈18000 galaxies, allowing us to probe galaxies with 0.1≲SFR≲100 M⊙ yr−1 and/or 108≲M∗≲1011 M⊙. We use sample-mean BHAR to approximate long-term average BHAR. Our sample-mean BHARs are derived from the Chandra Deep Field-South 7 Ms observations, while the SFRs and M∗ have been estimated by the CANDELS team through SED fitting. The average BHAR is correlated positively with both SFR and M∗, and the BHAR-SFR and BHAR-M∗ relations can both be described acceptably by linear models with a slope of unity. However, BHAR appears to be correlated more strongly with M∗ than SFR. This result indicates that M∗ is the primary host-galaxy property related to black-hole growth, and the apparent BHAR-SFR relation is largely a secondary effect due to the star-forming main sequence. Among our sources, massive galaxies (M∗≳1010M⊙) have significantly higher BHAR/SFR ratios than less-massive galaxies, indicating the former have higher black-hole fueling efficiency and/or higher SMBH occupation fraction than the latter. Our results can naturally explain the observed proportionality between MBH and M∗ for local giant ellipticals, and suggest their MBH/M∗ is higher than that of local star-forming galaxies. Among local star-forming galaxies, massive systems might have higher MBH/M∗ compared to dwarfs.

Citation

Yang, G., Chen, C., Vito, F., Brandt, W., Alexander, D., Luo, B., …Wang, J. (2017). Black Hole Growth Is Mainly Linked to Host-galaxy Stellar Mass Rather Than Star Formation Rate. Astrophysical Journal, 842(2), Article 72. https://doi.org/10.3847/1538-4357/aa7564

• Journal Article Type: Article
• Acceptance Date: May 25, 2017
• Online Publication Date: Jun 15, 2017
• Publication Date: Jun 15, 2017
• Deposit Date: Jun 21, 2017
• Publicly Available Date: Jun 30, 2017
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 842
• Issue: 2
• Article Number: 72
• DOI: https://doi.org/10.3847/1538-4357/aa7564
• Public URL: https://durham-repository.worktribe.com/output/1376521