The X-ray coronae in NuSTAR bright active galactic nuclei

Abstract

We present systematic and uniform analysis of NuSTAR data with 10-78 keV S/N > 50, of a sample of 60 SWIFT BAT selected AGNs, 10 of which are radio-loud. We measure their high energy cutoff Ecut or coronal temperature Te using three different spectral models to fit their NuSTAR spectra, and show a threshold in NuSTAR spectral S/N is essential for such measurements. High energy spectral breaks are detected in the majority of the sample, and for the rest strong constraints to Ecut or Te are obtained. Strikingly, we find extraordinarily large Ecut lower limits ( > 400 keV, up to > 800 keV) in 10 radio-quiet sources, whereas none in the radio-loud sample. Consequently and surprisingly, we find significantly larger mean Ecut/Te of radio-quiet sources compared with radio-loud ones. The reliability of these measurements are carefully inspected and verified with simulations. We find a strong positive correlation between Ecut and photon index Γ, which can not be attributed to the parameter degeneracy. The strong dependence of Ecut on Γ, which could fully account for the discrepancy of Ecut distribution between radio-loud and radio-quiet sources, indicates the X-ray coronae in AGNs with steeper hard X-ray spectra have on average higher temperature and thus smaller opacity. However, no prominent correlation is found between Ecut and λedd. In the l-Θ diagram, we find a considerable fraction of sources lie beyond the boundaries of forbidden regions due to runaway pair production, posing (stronger) challenges to various (flat) coronal geometries.

arXiv comment17 pages, 9 figures, accepted by ApJ. Comments are welcome!

References in corpus (54)

• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• Improved Reflection Models of Black-Hole Accretion Disks: Treating the Angular Distribution of X-rays
• The 105 month Swift-BAT all-sky hard X-ray survey
• Plasma Ejection from Magnetic Flares and the X-ray Spectrum of Cygnus X-1
• BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics
• Calibration of the NuSTAR High Energy Focusing X-ray Telescope
• NuSTAR Observations of the Bullet Cluster: Constraints on Inverse Compton Emission
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• Correlations between X-ray and radio spectral properties of accreting black holes
• ON THE GEOMETRY OF THE X-RAY EMITTING REGION IN SEYFERT GALAXIES
• On the evolution of the black hole:spheroid mass ratio
• The Cores of the Fe K$\alpha$ Lines in Active Galactic Nuclei: an Extended Chandra High Energy Grating Sample
• BAT AGN Spectroscopic Survey -- XII. The relation between coronal properties of Active Galactic Nuclei and the Eddington ratio
• Correlation between the photon index and X-ray luminosity of black hole X-ray binaries and active galactic nuclei: observations and interpretation
• The SDSS/XMM-Newton Quasar Survey: Correlation between X-ray spectral slope and Eddington ratio
• Testing Comptonization models using BeppoSAX observations of Seyfert 1 galaxies
• The mass of the black hole in Centaurus A from SINFONI AO-assisted integral-field observations of stellar kinematics
• Properties of AGN coronae in the NuSTAR era II: hybrid plasma
• A NuSTAR census of coronal parameters in Seyfert galaxies
• A dynamic black hole corona in an active galaxy through X-ray reverberation mapping
• Coupling between the accreting corona and the relativistic jet in the micro quasar GRS 1915+105
• The high-Eddington NLS1 Ark 564 has the coolest corona
• Black Hole Masses of Active Galaxies with Double-Peaked Balmer Emission Lines
• Are X-ray Emitting Coronae around Super Massive Black Holes Outflowing?
• First high energy observations of Narrow Line Seyfert 1s with INTEGRAL/IBIS
• The hard X-ray spectrum of NGC 5506 as seen by NuSTAR
• NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
• Anatomy of the AGN in NGC 5548 VIII. XMM-Newton's EPIC detailed view of an unexpected variable multilayer absorber
• NuSTAR Reveals the Comptonizing Corona of the Broad-Line Radio Galaxy 3C 382
• Revealing the accretion disc corona in Mrk 335 with multi-epoch X-ray spectroscopy
• X-ray Coronal Properties of Swift/BAT-Selected Seyfert 1 Active Galactic Nuclei
• On Estimating the High-Energy Cutoff in the X-ray Spectra of Black Holes via Reflection Spectroscopy
• High-energy monitoring of NGC 4593 with XMM-Newton and NuSTAR. X-ray spectral analysis
• 3C 273 with NuSTAR: Unveiling the AGN
• High-energy monitoring of NGC 4593 II. Broadband spectral analysis: testing the two-corona model
• NuSTAR reveals the extreme properties of the super-Eddington accreting SMBH in PG 1247+267
• Coronal properties of Swift/BAT-selected Seyfert 1 AGN observed with NuSTAR
• Swift/XRT- NuSTAR spectra of type 1 AGN]{Swift/XRT- NuSTAR spectra of type 1 AGN: confirming INTEGRAL results on the high energy cut-off
• Fundamental X-ray Corona Parameters of Swift/BAT AGN
• The first simultaneous X-ray broad-band view of Mrk 110 with XMM-Newton and NuSTAR
• NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901
• NuSTAR hard X-ray spectra of radio galaxies
• Multi-epoch analysis of the X-ray spectrum of the active galactic nucleus in NGC 5506
• NuSTAR view of Swift/BAT AGN: The $R$-$\Gamma$ correlation
• Long term X-Ray Observations of Seyfert 1 Galaxy Ark 120: On the origin of soft-excess
• Study of X-ray variability and coronae of Seyfert galaxies using NuSTAR
• Distinct High Energy Cutoff Variation Patterns in Two Seyfert Galaxies
• Repeated pattern of gamma-ray flares in the lightcurve of the blazar 3C 279
• On Measuring the Variation of High Energy Cut-off in Active Galactic Nuclei
• A deep X-ray view of the bare AGN Ark 120. VI. Geometry of the hot corona from spectroscopic and polarization signatures
• Nustar view of the central region of the Perseus cluster
• Detection of the high energy cut-off from the Seyfert 1.5 galaxy NGC 5273
• More than softer-when-brighter: the X-Ray powerlaw spectral variability in NGC 4051

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