NuSTAR reveals the Comptonizing corona of the broad-line radio galaxy 3C 382
- Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)
- Harvard-Smithsonian CfA, 60 Garden Street MS-67, Cambridge, MA 02138 (United States)
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
- Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)
- DTU SpaceNational Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark)
- Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom)
- Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
- Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy)
- NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
Broad-line radio galaxies (BLRGs) are active galactic nuclei that produce powerful, large-scale radio jets, but appear as Seyfert 1 galaxies in their optical spectra. In the X-ray band, BLRGs also appear like Seyfert galaxies, but with flatter spectra and weaker reflection features. One explanation for these properties is that the X-ray continuum is diluted by emission from the jet. Here, we present two NuSTAR observations of the BLRG 3C 382 that show clear evidence that the continuum of this source is dominated by thermal Comptonization, as in Seyfert 1 galaxies. The two observations were separated by over a year and found 3C 382 in different states separated by a factor of 1.7 in flux. The lower flux spectrum has a photon-index of Γ=1.68{sub −0.02}{sup +0.03}, while the photon-index of the higher flux spectrum is Γ=1.78{sub −0.03}{sup +0.02}. Thermal and anisotropic Comptonization models provide an excellent fit to both spectra and show that the coronal plasma cooled from kT{sub e} = 330 ± 30 keV in the low flux data to 231{sub −88}{sup +50} keV in the high flux observation. This cooling behavior is typical of Comptonizing corona in Seyfert galaxies and is distinct from the variations observed in jet-dominated sources. In the high flux observation, simultaneous Swift data are leveraged to obtain a broadband spectral energy distribution and indicates that the corona intercepts ∼10% of the optical and ultraviolet emitting accretion disk. 3C 382 exhibits very weak reflection features, with no detectable relativistic Fe Kα line, that may be best explained by an outflowing corona combined with an ionized inner accretion disk.
- OSTI ID:
- 22370460
- Journal Information:
- Astrophysical Journal, Vol. 794, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
NuSTAR and XMM-Newton observations of the hard X-ray spectrum of Centaurus A
Rapid variability of blazar 3C 279 during flaring states in 2013−2014 with joint Fermi-LAT, NuSTAR, Swift, and ground-based multi-wavelength observations