%0 Journal Article
%T Measuring the Coronal Properties of IC4329A with NuSTAR
%A L. W. Brenneman
%A G. Madejski
%A F. Fuerst
%A G. Matt
%A M. Elvis
%A F. A. Harrison
%A D. R. Ballantyne
%A S. E. Boggs
%A F. E. Christensen
%A W. W. Craig
%A A. C. Fabian
%A B. W. Grefenstette
%A C. J. Hailey
%A K. K. Madsen
%A A. Marinucci
%A E. Rivers
%A D. Stern
%A D. J. Walton
%A W. W. Zhang
%J Physics
%D 2013
%I arXiv
%R 10.1088/0004-637X/781/2/83
%X We present an analysis of a ~160 ks NuSTAR observation of the nearby bright Seyfert galaxy IC4329A. The high-quality broadband spectrum enables us to separate the effects of distant reflection from the direct coronal continuum, and to therefore accurately measure the high-energy cutoff to be $E_{cut}=178^{+74}_{-40}$ keV. The coronal emission arises from accretion disk photons Compton up-scattered by a thermal plasma, with the spectral index and cutoff being due to a combination of the finite plasma temperature and optical depth. Applying standard Comptonization models, we measure both physical properties independently using the best signal-to-noise obtained to date in an AGN over the 3-79 keV band. We derive $kT_e=37^{+7}_{-6}$ keV with $\tau=1.25^{+0.20}_{-0.10}$ assuming a slab geometry for the plasma, and $kT_e=33^{+6}_{-6}$ keV with $\tau=3.41^{+0.58}_{-0.38}$ for a spherical geometry, with both having an equivalent goodness-of-fit.
%U http://arxiv.org/abs/1312.3563v1