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A Long Look at MCG-5-23-16 with NuSTAR. I. Relativistic Reflection and Coronal Properties

Zoghbi, Abderahmen and Matt, G. and Miller, J. M. and Lohfink, A. M. and Walton, D. J. and Ballantyne, D. R. and García, J. A. and Stern, D. and Koss, M. J. and Farrah, D. and Harrison, F. A. and Boggs, S. E. and Christensen, F. E. and Craig, W. and Hailey, C. J. and Zhang, W. W. (2017) A Long Look at MCG-5-23-16 with NuSTAR. I. Relativistic Reflection and Coronal Properties. Astrophysical Journal, 836 (1). Art. No. 2. ISSN 0004-637X.

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MCG-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.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Zoghbi, Abderahmen0000-0002-0572-9613
Matt, G.0000-0002-2152-0916
Walton, D. J.0000-0001-5819-3552
Ballantyne, D. R.0000-0001-8128-6976
García, J. A.0000-0003-3828-2448
Stern, D.0000-0003-2686-9241
Koss, M. J.0000-0002-7998-9581
Farrah, D.0000-0003-1748-2010
Harrison, F. A.0000-0003-2992-8024
Boggs, S. E.0000-0001-9567-4224
Christensen, F. E.0000-0001-5679-1946
Zhang, W. W.0000-0002-1426-9698
Additional Information:© 2017 The American Astronomical Society. Received 2016 September 22; revised 2017 January 3; accepted 2017 January 6; published 2017 February 3. We thank the referee, A. Zdziarski, for the useful comments and suggestions that helped with the interpretation of the data. This work has been partly supported by NASA grant NNX14AF89G. This work made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA).
Group:Space Radiation Laboratory, NuSTAR, Astronomy Department
Funding AgencyGrant Number
Subject Keywords:black hole physics – galaxies: active – galaxies: individual (MCG-5-23-16) – galaxies: Seyfert
Issue or Number:1
Record Number:CaltechAUTHORS:20170206-142411468
Persistent URL:
Official Citation:Abderahmen Zoghbi et al 2017 ApJ 836 2
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:74094
Deposited By: Tony Diaz
Deposited On:07 Feb 2017 00:01
Last Modified:09 Mar 2020 13:19

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