T. Z. Zhang

Publications (3)0 Total impact

• Article: arXiv:astro-ph/0203158

  Xue-Bing Wu, F. K. Liu, T. Z. Zhang
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  ABSTRACT: The recently discovered tight correlation between supermassive black hole mass and central velocity dispersion for both inactive and active galaxies suggests a possibility to estimate the black hole mass from the measured central velocity dispersion. However, for most AGNs it is dicult to measure the central velocity dispersions of their host galaxies directly with the spectroscopic studies. In this paper we adopt the fundamental plane for ellipticals to estimate the central velocity dispersion and black hole mass for a number of AGNs with morphology parameters of their elliptical host galaxies obtained by the Hubble Space Telescope imaging observations.
  04/2002;
• Source

  Available from: arxiv.org

  Article: Supermassive Black Hole Masses of AGNs with Elliptical Hosts

  Xue-Bing Wu, F. K. Liu, T. Z. Zhang
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  ABSTRACT: The recently discovered tight correlation between supermassive black hole mass and central velocity dispersion suggests a possibility to estimate the SMBH mass from the measured central velocity dispersion. However, for most AGNs it is difficult to measure the central velocity dispersions of their host galaxies directly. In this paper we adopt the fundamental plane for ellipticals to estimate the central velocity dispersion and SMBH mass for a number of AGNs with morphology parameters of their elliptical host galaxies obtained by the HST imaging observations. The estimated SMBH masses of 63 BL Lac objects, 10 radio galaxies, 10 radio-loud quasars and 9 radio-quiet quasars are mostly in the range of $10^{7.5} M_\odot$ to $10^{9} M_\odot$. No significant difference in black hole mass is found for high-frequency peaked BL Lacs and low-frequency peaked BL Lacs, as well as for radio galaxies and radio-loud quasars. The Eddington ratios of radio galaxies are substantially smaller than those of quasars. This suggests that the different observational features of radio-loud AGNs may be mainly dominated by accretion rate rather than by the black hole mass, which is in agreement with some evolutionary scenarios recently proposed for radio-loud AGNs. Different from some previous claims, we found that the derived mean SMBH mass for radio-loud quasars is only slightly larger than that of radio-quiet quasars. Though their SMBH mass distributions are statistically different, their Eddington ratio distributions are probably from the same population. In addition, we noted that the relation between black hole mass and host galaxy luminosity obtained using the fundamental plane provides further arguments for a nonlinear scaling law between SMBH and galactic bulge mass. Comment: 9 pages, A&A accepted
  03/2002;
• Source

  Available from: articles.adsabs.harvard.edu

  Article: Supermassive Black Hole Masses and Bulge Luminosities of AGNs

  X.-B. Wu, J. L. Han, F. K. Liu, T. Z. Zhang
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  ABSTRACT: Using the tight correlation between black hole mass and central velocity dispersion, we estimated the supermassive black hole (SMBH) masses for 65 Seyfert galaxies, 63 BL Lacertae objects, 10 radio galaxies, 10 radio-loud quasars and 9 radio-quiet quasars. The SMBH masses of Seyfert galaxies were found to be from 106 Msun to 108.5 Msun. No significant difference was found for the black hole masses of radio-loud AGNs, which are mostly in the range of 107.5 Msun to 109 Msun. By studying the correlation between the SMBH mass and the host galaxy luminosity, we confirmed a possible universal nonlinear scaling law between SMBH and galactic bulge masses, which is consistent with the implications of some theoretical models on supermassive black hole and galaxy formation.
  -1:405-406.