Journal article · Preprint article
A long look at MCG-5-23-16 with NuSTAR. I. relativistic reflection and coronal properties
University of Michigan, Ann Arbor1
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark2
Columbia University3
NASA Goddard Space Flight Center4
Università Roma Tre5
University of Cambridge6
California Institute of Technology7
Georgia Institute of Technology8
Swiss Federal Institute of Technology Zurich9
Virginia Polytechnic Institute and State University10
University of California at Berkeley11
National Space Institute, Technical University of Denmark12
...and 2 moreMCG-5-23-16 was targeted in early 2015 with a half mega-second observing campaign using NuSTAR. Here we present the spectral analysis of these data sets along with an earlier observation and study the relativistic reflection and the primary coronal source. The data show strong reflection features in the form of both narrow and broad iron lines plus a Compton reflection hump.
A cutoff energy is significantly detected in all exposures. The shape of the reflection spectrum does not change in the two years spanned by the observations, suggesting a stable geometry. A strong positive correlation is found between the cutoff energy and both the hard X-ray flux and spectral index.
The measurements imply that the coronal plasma is not at the runaway electron-positron pair limit, and instead contains mostly electrons. The observed variability in the coronal properties is driven by a variable optical depth. A constant heating-to-cooling ratio is measured, implying that there is a feedback mechanism in which a significant fraction of the photons cooling the corona are due to reprocessed hard X-rays.
Language: | English |
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Publisher: | American Astronomical Society |
Year: | 2017 |
Pages: | 2 |
ISSN: | 15384357 and 0004637x |
Types: | Journal article and Preprint article |
DOI: | 10.3847/1538-4357/aa582c |
ORCIDs: | 0000-0002-0572-9613 , 0000-0002-2152-0916 , 0000-0001-5819-3552 , 0000-0001-8128-6976 , 0000-0003-3828-2448 , 0000-0003-2686-9241 , 0000-0002-7998-9581 , 0000-0001-6854-7545 , 0000-0003-2992-8024 and Christensen, Finn Erland |