Investigating the Covering Fraction Distribution of Swift/BAT AGN with X-ray and IR Observations. (arXiv:1811.02570v1 [astro-ph.GA])

Investigating the Covering Fraction Distribution of Swift/BAT AGN with X-ray and IR Observations. (arXiv:1811.02570v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lanz_L/0/1/0/all/0/1">Lauranne Lanz</a> (Dartmouth), <a href="http://arxiv.org/find/astro-ph/1/au:+Hickox_R/0/1/0/all/0/1">Ryan C. Hickox</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balokovic_M/0/1/0/all/0/1">Mislav Balokovi&#x107;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shimizu_T/0/1/0/all/0/1">Taro Shimizu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricci_C/0/1/0/all/0/1">Claudio Ricci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goulding_A/0/1/0/all/0/1">Andy D. Goulding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ballantyne_D/0/1/0/all/0/1">David R. Ballantyne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bauer_F/0/1/0/all/0/1">Franz E. Bauer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_C/0/1/0/all/0/1">Chien-Ting J. Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moro_A/0/1/0/all/0/1">Agnese Del Moro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Farrah_D/0/1/0/all/0/1">Duncan Farrah</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Koss_M/0/1/0/all/0/1">Michael J. Koss</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+LaMassa_S/0/1/0/all/0/1">Stephanie LaMassa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masini_A/0/1/0/all/0/1">Alberto Masini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zappacosta_L/0/1/0/all/0/1">Luca Zappacosta</a>

We present an analysis of a sample of 69 local obscured Swift/BAT active
galactic nuclei (AGN) with X-ray spectra from NuSTAR and IR spectral energy
distributions from Herschel and WISE. We combine this X-ray and IR
phenomenological modeling and find a significant correlation between reflected
hard X-ray emission and IR AGN emission, with suggestive indications that this
correlation may be stronger than the one between intrinsic hard X-ray and IR
emissions. This relation between the IR and reflected X-ray emission suggests
that both are the result of the processing of intrinsic emission from the
corona and accretion disk by the same structure. We explored the resulting
implications on the underlying distribution of covering fraction for all AGN,
by generating mock observables for the reflection parameter and IR luminosity
ratio using empirical relations found for the covering fraction with each
quantity. We find that the observed distributions of the reflection parameter
and IR-to-X-ray ratio are reproduced with broad distributions centered around
covering fractions of at least ~40-50%, while narrower distributions only match
our observations when centered around covering fractions of ~70-80%. Our
results are consistent with both independent estimates of the covering
fractions of individual objects and the typical covering fraction obtained
based on obscured fractions for samples of AGN. These results suggest that the
level of reprocessing in AGN, including X-ray reflection, is related in a
relatively straightforward way to the geometry of the obscuring material.

We present an analysis of a sample of 69 local obscured Swift/BAT active
galactic nuclei (AGN) with X-ray spectra from NuSTAR and IR spectral energy
distributions from Herschel and WISE. We combine this X-ray and IR
phenomenological modeling and find a significant correlation between reflected
hard X-ray emission and IR AGN emission, with suggestive indications that this
correlation may be stronger than the one between intrinsic hard X-ray and IR
emissions. This relation between the IR and reflected X-ray emission suggests
that both are the result of the processing of intrinsic emission from the
corona and accretion disk by the same structure. We explored the resulting
implications on the underlying distribution of covering fraction for all AGN,
by generating mock observables for the reflection parameter and IR luminosity
ratio using empirical relations found for the covering fraction with each
quantity. We find that the observed distributions of the reflection parameter
and IR-to-X-ray ratio are reproduced with broad distributions centered around
covering fractions of at least ~40-50%, while narrower distributions only match
our observations when centered around covering fractions of ~70-80%. Our
results are consistent with both independent estimates of the covering
fractions of individual objects and the typical covering fraction obtained
based on obscured fractions for samples of AGN. These results suggest that the
level of reprocessing in AGN, including X-ray reflection, is related in a
relatively straightforward way to the geometry of the obscuring material.

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