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The black hole spins of quasars

Published online by Cambridge University Press:  07 March 2016

Bei You  and
Xinwu Cao
Bei You
Affiliation:
Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030, China email: [email protected] University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
Xinwu Cao
Affiliation:
Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030, China email: [email protected]
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Abstract

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We present the estimates of the black hole spins of five quasars. The peaks of the spectra of the accretion discs surrounding massive black holes in quasars are in the far-UV or soft X-ray band, which are usually not observed. However, in the disc corona model, the soft photons from the disc are Comptonized to high energy in the hot corona, and the hard X-ray spectra (luminosity and spectral shape) contain the information of the incident spectra from the disc. The values of black hole spin parameter a are inferred from the spectral fitting, which spread over a large range, ~ −0.94 to 0.998.

Keywords

galaxies: nucleigalaxies: kinematics and dynamicsmethods: numerical
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 10 , Issue S312: Star Clusters and Black Holes in Galaxies across Cosmic Time , August 2014 , pp. 143 - 144
Copyright
Copyright © International Astronomical Union 2016 

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