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arXiv · 1208.1612

Contribution of the accretion disk, hot corona, and obscuring torus to the luminosity of Seyfert galaxies: INTEGRAL and Spitzer observations

S. Sazonov·S. P. Willner·A. D. Goulding·R. C. Hickox·V. Gorjian·M. W. Werner·E. Churazov·R. Krivonos·M. Revnivtsev·R. Sunyaev·C. Jones·S. S. Murray·A. Vikhlinin·A. C. Fabian·W. R. Forman
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Abstract

We estimate the relative contributions of the supermassive black hole (SMBH) accretion disk, corona, and obscuring torus to the bolometric luminosity of Seyfert galaxies, using Spizter mid-infrared (MIR) observations of a complete sample of 68 nearby active galactic nuclei from the INTEGRAL all-sky hard X-ray (HX) survey. This is the first HX-selected (above 15 keV) sample of AGNs with complementary high angular resolution, high signal to noise, MIR data. Correcting for the host galaxy contribution, we find a correlation between HX and MIR luminosities: L_MIR L_HX^(0.74+/-0.06). Assuming that the observed MIR emission is radiation from an accretion disk reprocessed in a surrounding dusty torus that subtends a solid angle decreasing with increasing luminosity (as inferred from the declining fraction of obscured AGNs), the intrinsic disk luminosity, L_D, is approximately proportional to the luminosity of the corona in the 2-300 keV energy band, L_C, with the L_D/L_C ratio varying by a factor of 2.1 around a mean value of 1.6. This ratio is a factor of ~2 smaller than for typical quasars producing the cosmic X-ray background (CXB). Therefore, over three orders of magnitude in luminosity, HX radiation carries a large, and roughly comparable, fraction of the bolometric output of AGNs. We estimate the cumulative bolometric luminosity density of local AGNs at ~(1-3)x10^40 erg/s/Mpc^3. Finally, the Compton temperature ranges between kT_c~2 and ~6 keV for nearby AGNs, compared to kT_c~2 keV for typical quasars, confirming that radiative heating of interstellar gas can play an important role in regulating SMBH growth.

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S. Sazonov, S. P. Willner, A. D. Goulding, R. C. Hickox, V. Gorjian, M. W. Werner, E. Churazov, R. Krivonos, M. Revnivtsev, R. Sunyaev, C. Jones, S. S. Murray, A. Vikhlinin, A. C. Fabian, W. R. Forman. 2012-08-08. Contribution of the accretion disk, hot corona, and obscuring torus to the luminosity of Seyfert galaxies: INTEGRAL and Spitzer observations. https://doi.org/10.1088/0004-637x/757/2/181

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