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 Spitzer mid-infrared ( MIR ) observations of a complete sample of 68 nearby active galactic nuclei ( AGNs ) 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 _ { 15 \mum } \propto L _ { HX } ^ { 0.74 \pm 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 _ { Disk } , is approximately proportional to the luminosity of the corona in the 2–300 keV energy band , L _ { Corona } , with the L _ { Disk } / L _ { Corona } ratio varying by a factor of 2.1 around a mean value of 1.6 .
This ratio is a factor of { \sim } 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 { \sim } ( 1 - 3 ) \times 10 ^ { 40 } erg s ^ { -1 } Mpc ^ { -3 } .
Finally , the Compton temperature ranges between kT _ { c } \approx 2 and \approx 6 keV for nearby AGNs , compared to kT _ { c } \approx 2 keV for typical quasars , confirming that radiative heating of interstellar gas can play an important role in regulating SMBH growth .