A Caltech Library Service

Measuring the Coronal Properties of IC 4329A with NuSTAR

Brenneman, L. W. and Madejski, G. and Fuerst, F. and Matt, G. and Elvis, M. and Harrison, F. A. and Ballantyne, D. R. and Boggs, S. E. and Christensen, F. E. and Craig, W. W. and Fabian, A. C. and Grefenstette, B. W. and Hailey, C. J. and Madsen, K. K. and Marinucci, A. and Rivers, E. and Stern, D. and Walton, D. J. and Zhang, W. W. (2014) Measuring the Coronal Properties of IC 4329A with NuSTAR. Astrophysical Journal, 781 (2). Art. No. 83. ISSN 0004-637X. doi:10.1088/0004-637X/781/2/83.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present an analysis of a ~160 ks NuSTAR observation of the nearby bright Seyfert galaxy IC 4329A. 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 active galactic nucleus over the 3-79 keV band. We derive kT_e=37^(+7)_(-6) keV with τ =1.25^(+0.20)_(-0.10) assuming a slab geometry for the plasma, and kT_e=33^(+6)_(-6)keV with τ = 3.41^(+0.58)_(-0.38) for a spherical geometry, with both having an equivalent goodness-of-fit.

Item Type:Article
Related URLs:
URLURL TypeDescription
Fuerst, F.0000-0003-0388-0560
Matt, G.0000-0002-2152-0916
Harrison, F. A.0000-0003-2992-8024
Ballantyne, D. R.0000-0001-8128-6976
Boggs, S. E.0000-0001-9567-4224
Christensen, F. E.0000-0001-5679-1946
Fabian, A. C.0000-0002-9378-4072
Grefenstette, B. W.0000-0002-1984-2932
Madsen, K. K.0000-0003-1252-4891
Stern, D.0000-0003-2686-9241
Walton, D. J.0000-0001-5819-3552
Zhang, W. W.0000-0002-1426-9698
Additional Information:© 2014 American Astronomical Society. Received 2013 October 18; accepted 2013 December 11; published 2014 January 13. This work was supported under NASA Contract No. NNG08FD60C, and 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). L.B. gratefully acknowledges funding from NASA grant NNX13AE90G. G.M. and A.M. acknowledge financial support from the Italian Space Agency under contract ASI/INAF I/037/12/0-011/13.
Group:NuSTAR, Space Radiation Laboratory
Funding AgencyGrant Number
Agenzia Spaziale Italiana (ASI)I/037/12/0-011/13
Subject Keywords:accretion, accretion disks; galaxies: active; galaxies: individual (IC 4329A); galaxies: nuclei; galaxies: Seyfert; X-rays: galaxies
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2014-71
Issue or Number:2
Record Number:CaltechAUTHORS:20140320-153441616
Persistent URL:
Official Citation:Measuring the Coronal Properties of IC 4329A with NuSTAR L. W. Brenneman et al. 2014 ApJ 781 83
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:44432
Deposited By: Ruth Sustaita
Deposited On:21 Mar 2014 16:02
Last Modified:10 Nov 2021 16:52

Repository Staff Only: item control page