About SciDoc
Document Search

DOCUMENT METADATA
SLAC Publication: SLAC-PUB-16150
SLAC Release Date: November 20, 2014
Measuring the Coronal Properties of IC 4329A with NuSTAR
Brenneman, Laura.
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 plas... Show Full Abstract
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. Show Partial Abstract
Download File:
  • Interest Categories: Astrophysics