NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-18 T11:39:51 PDT
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For refcode 2015ApJ...812..113G:
Retrieve 13 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2015ApJ...812..113G The Dust Sublimation Radius as an Outer Envelope to the Bulk of the Narrow Fe Kalpha Line Emission in Type 1 AGNs Gandhi, Poshak; Honig, Sebastian F.; Kishimoto, Makoto Abstract. The Fe Kalpha emission line is the most ubiquitous feature in the X-ray spectra of active galactic nuclei (AGNs), but the origin of its narrow core remains uncertain. Here, we investigate the connection between the sizes of the Fe Kalpha core emission regions and the measured sizes of the dusty tori in 13 local Type 1 AGNs. The observed Fe Kalpha emission radii (R_Fe_) are determined from spectrally resolved line widths in X-ray grating spectra, and the dust sublimation radii (R_dust_) are measured either from optical/near-infrared (NIR) reverberation time lags or from resolved NIR interferometric data. This direct comparison shows, on an object-by-object basis, that the dust sublimation radius forms an outer envelope to the bulk of the Fe Kalpha emission. R_Fe_ matches R_dust_ well in the AGNs, with the best constrained line widths currently. In a significant fraction of objects without a clear narrow line core, R_Fe_ is similar to, or smaller than, the radius of the optical broad line region. These facts place important constraints on the torus geometries for our sample. Extended tori in which the solid angle of fluorescing gas peaks at well beyond the dust sublimation radius can be ruled out. We also test for luminosity scalings of R_Fe_, finding that the Eddington ratio is not a prime driver in determining the line location in our sample. We also discuss in detail potential caveats of data analysis and instrumental limitations, simplistic line modeling, uncertain black hole masses, and sample selection, showing that none of these is likely to bias our core result. The calorimeter on board Astro-H will soon vastly increase the parameter space over which line measurements can be made, overcoming many of these limitations. Key words: galaxies: active, infrared: galaxies, X-rays: galaxies
Retrieve 13 NED objects in this reference.
Please click here for ADS abstract

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