Browsing by Author "Chen, C-T J."

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    Does black hole growth depend fundamentally on host-galaxy compactness?
    (2019) Ni, Q.; Yang, G.; Brandt, W. N.; Alexander, D. M.; Chen, C-T J.; Luo, B.; Vito, F.; Xue, Y. Q.
    Possible connections between central black hole (BH) growth and host-galaxy compactness have been found observationally, which may provide insight into BH-galaxy coevolution: compact galaxies might have large amounts of gas in their centres due to their high mass-to-size ratios, and simulations predict that high central gas density can boost BH accretion. However, it is not yet clear if BH growth is fundamentally related to the compactness of the host galaxy, due to observational degeneracies between compactness, stellar mass (M-star) and star formation rate (SFR). To break these degeneracies, we carry out systematic partial-correlation studies to investigate the dependence of sample-averaged BH accretion rate ((BHAR) over bar) on the compactness of host galaxies, represented by the surface-mass density, Sigma(e), or the projected central surface-mass density within 1 kpc, Sigma(1). We utilize 8842 galaxies with H < 24.5 in the five CANDELS fields at z = 0.5-3. We find that <(BHAR)over bar> does not significantly depend on compactness when controlling for SFR or M-star among bulge-dominated galaxies and galaxies that are not dominated by bulges, respectively. However, when testing is confined to star-forming galaxies at z = 0.5-1.5, we find that the (BHAR) over bar-Sigma(1) relation is not simply a secondary manifestation of a primary (BHAR) over bar -M-star relation, which may indicate a link between BH growth and the gas density within the central 1 kpc of galaxies.
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    Revealing the relation between black hole growth and host-galaxy compactness among star-forming galaxies
    (2021) Ni, Q.; Brandt, W. N.; Yang, G.; Leja, J.; Chen, C-T J.; Luo, B.; Matharu, J.; Sun, M.; Vito, F.; Xue, Y. Q.; Zhang, K.
    Recent studies show that a universal relation between black hole (BH) growth and stellar mass (M-*) or star formation rate (SFR) is an oversimplification of BH-galaxy coevolution, and that morphological and structural properties of host galaxies must also be considered. Particularly, a possible connection between BH growth and host-galaxy compactness was identified among star-forming (SF) galaxies. Utilizing approximate to 6300 massive galaxies with I-814W < 24 at z < 1.2 in the Cosmic Evolution Survey (COSMOS) field, we perform systematic partial correlation analyses to investigate how sample-averaged BH accretion rate (BHAR) depends on host-galaxy compactness among SF galaxies, when controlling for morphology and M-* (or SFR). The projected central surface mass density within 1 kpc, Sigma(1), is utilized to represent host-galaxy compactness in our study. We find that the BHAR-Sigma(1) relation is stronger than either the BHAR-M-* or BHAR-SFR relation among SF galaxies, and this BHAR-Sigma(1) relation applies to both bulge-dominated galaxies and galaxies that are not dominated by bulges. This BHAR-Sigma(1) relation among SF galaxies suggests a link between BH growth and the central gas density of host galaxies on the kpc scale, which may further imply a common origin of the gas in the vicinity of the BH and in the central similar to kpc of the galaxy. This BHAR-Sigma(1) relation can also be interpreted as the relation between BH growth and the central velocity dispersion of host galaxies at a given gas content (i.e. gas mass fraction), indicating the role of the host-galaxy potential well in regulating accretion on to the BH.
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    The XMM-SERVS survey: new XMM-Newton point-source catalogue for the XMM-LSS field
    (2018) Chen, C-T J.; Brandt, W. N.; Luo, B.; Ranalli, P.; Yang, G.; Alexander, D. M.; Bauer, Franz Erik; Kelson, D. D.; Lacy, M.; Nyland, K.; Tozzi, P.; Vito, F.; Cirasuolo, M.; Gilli, R.; Jarvis, M. J.; Lehmer, B. D.; Paolillo, M.; Schneider, D. P.|