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A Long Look at MCG-5-23-16 with NuSTAR. I. Relativistic Reflection and Coronal PropertiesMCG-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.
Document ID
Document Type
Reprint (Version printed in journal)
Zoghbi, Abderahmen (Michigan Univ. Ann Arbor, MI, United States)
Matt, G. (Universita degli Studi Roma Tre Rome, Italy)
Miller, J. M. (Michigan Univ. Ann Arbor, MI, United States)
Lohfink, A. M. (Cambridge Univ. Cambridge, United Kingdom)
Walton, D. J. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ballantyne, D. R. (Georgia Inst. of Tech. Atlanta, GA, United States)
Garcia, J. A. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Stern, D. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Koss, M. J. (Eidgenoessische Technische Hochschule Zurich, Switzerland)
Farrah, D. (Virginia Tech Blacksburg, VA, United States)
Harrison, F. A. (California Inst. of Tech. Pasadena, CA, United States)
Boggs, S. E. (California Univ. Berkeley, CA, United States)
Christensen, F. E. (Technical Univ. of Denmark Lyngby, Denmark)
Craig, W. (California Univ. Berkeley, CA, United States)
Hailey, C. J. (Columbia Univ. New York, NY, United States)
Zhang, W. W. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
July 7, 2017
Publication Date
February 3, 2017
Publication Information
Publication: The Astrophysical Journal
Volume: 836
Issue: 1
ISSN: 0004-637X
Subject Category
Statistics and Probability
Report/Patent Number
Funding Number(s)
Distribution Limits
black hole physics – galaxies: active – galaxies: individual (MCG-5-23-16) â