Previous studies suggest that the growth of supermassive black holes (SMBHs) may be fundamentally related to host-galaxy stellar mass (M*). To investigate this SMBH growth-M* relation in detail, we calculate long-term SMBH accretion rate as a function of M* and redshift [BHAR(M*, z)] over ranges of log (M*/M⊙) = 9.5-12 and z = 0.4-4. Our BHAR(M*, z) is constrained by high-quality survey data (GOODS-South, GOODS-North and COSMOS), and by the stellar mass function and the X-ray luminosity function. At a given M*, BHAR is higher at high redshift. This redshift dependence is stronger in more massive systems [for log (M*/M⊙) ≈ 11.5, BHAR is three decades higher at z = 4 than at z = 0.5], possibly due to AGN feedback. Our results indicate that the ratio between BHAR and average star formation rate (SFR) rises towards high M* at a given redshift. This BHAR/SFR dependence on M* does not support the scenario that SMBH and galaxy growth are in lockstep. We calculate SMBH mass history [MBH(z)] based on our BHAR(M*, z) and the M*(z) from the literature, and find that the MBH-M* relation has weak redshift evolution since z ≈ 2. The MBH/M* ratio is higher towards massive galaxies: it rises from ≈1/5000 at logM* ≲ 10.5 to ≈1/500 at logM* ≳ 11.2. Our predicted MBH/M* ratio at high M* is similar to that observed in local giant ellipticals, suggesting that SMBH growth from mergers is unlikely to dominate over growth from accretion.
Yang, G., Brandt, W., Vito, F., Chen, C., Trump, J., Luo, B., et al. (2018). Linking black hole growth with host galaxies: The accretion-stellar mass relation and its cosmic evolution. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 475(2), 1887-1911 [10.1093/mnras/stx2805].
Linking black hole growth with host galaxies: The accretion-stellar mass relation and its cosmic evolution
Vignali, C.Membro del Collaboration Group
;
2018
Abstract
Previous studies suggest that the growth of supermassive black holes (SMBHs) may be fundamentally related to host-galaxy stellar mass (M*). To investigate this SMBH growth-M* relation in detail, we calculate long-term SMBH accretion rate as a function of M* and redshift [BHAR(M*, z)] over ranges of log (M*/M⊙) = 9.5-12 and z = 0.4-4. Our BHAR(M*, z) is constrained by high-quality survey data (GOODS-South, GOODS-North and COSMOS), and by the stellar mass function and the X-ray luminosity function. At a given M*, BHAR is higher at high redshift. This redshift dependence is stronger in more massive systems [for log (M*/M⊙) ≈ 11.5, BHAR is three decades higher at z = 4 than at z = 0.5], possibly due to AGN feedback. Our results indicate that the ratio between BHAR and average star formation rate (SFR) rises towards high M* at a given redshift. This BHAR/SFR dependence on M* does not support the scenario that SMBH and galaxy growth are in lockstep. We calculate SMBH mass history [MBH(z)] based on our BHAR(M*, z) and the M*(z) from the literature, and find that the MBH-M* relation has weak redshift evolution since z ≈ 2. The MBH/M* ratio is higher towards massive galaxies: it rises from ≈1/5000 at logM* ≲ 10.5 to ≈1/500 at logM* ≳ 11.2. Our predicted MBH/M* ratio at high M* is similar to that observed in local giant ellipticals, suggesting that SMBH growth from mergers is unlikely to dominate over growth from accretion.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
