NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-20 T22:56:22 PDT
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For refcode 1995ApJ...440..610S:
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Copyright by American Astronomical Society. Reproduced by permission
1995ApJ...440..610S EMISSION SPECTRUM INTEGRATED OVER AN ACCRETION DISK: COMPARISON WITH OBSERVATIONS OF ACTIVE GALACTIC NUCLEI TOSHIYA SHIMURA AND FUMIO TAKAHARA Department of Physics, Tokyo Metropolitan University, Minamiohsawa 1-1, Hachioji-shi, Tokyo 192-03, Japan Received 1994 March 21; accepted 1994 August 29 ABSTRACT Emission spectrum from an accretion disk for active galactic nuclei is obtained by solving the vertical structure and radiative transfer self-consistently and by integrating the local spectrum over radii. We found that even for moderate accretion rates, disks emit a significant portion of the total luminosity in UV through soft X-ray range; for the accretion rate close to the Eddington limit, soft X-ray luminosity for a 0.1-2.0 keV range amounts to 57%, 43%, and 33% of the total luminosity for a black hole mass of 10^7^, 10^8^, and 10^9^ M_sun_, respectively. We compared our numerical results with IUE, Einstein, EXOSAT, and ROSAT observations of low-redshift quasars and Seyfert 1 galaxies and found that our results can statistically account for observations of the UV bump and soft X-ray excess simultaneously without exceeding the Eddington limit. We also performed a detailed spectral fit to the quasar H1821 +643, for which the estimated values of the black hole mass and accretion rate are 1.5 x 10^9^ M_sun_ and 0.7L_Edd_, respectively. Subject headings: accretion, accretion disks - galaxies: nuclei - radiation mechanisms: nonthermal - ultraviolet: galaxies - X-rays: galaxies
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