Nustar Measurement Of Coronal Temperature In Two Luminous, High Redshift Qsos

Abstract

X-ray emission from AGN is believed to be produced via Comptonization of optical/UV seed photons emitted by the accretion disk, up-scattered by hot electrons in a corona surrounding the black hole. A critical compactness vs. temperature threshold is predicted above which any increase in the source luminosity, for a fixed size, would then generate positron-electron pairs rather than continue heating the coronal plasma. Current observations seem to confirm that all AGN populate the region below this critical line. These models, however, have never been probed by observations in the high-luminosity regime, where the critical line is expected to reach low temperatures. To fill this observational gap, we selected two luminous ($log(L_{bol})>47.5$ erg/s) quasars, 2MASSJ1614346+470420 ($z=1.86$) and B1422+231 ($z=3.62$), and obtained XMM-Newton and NuSTAR deep observations for them. We performed detailed spectral analysis of their quasi-simultaneous soft and hard X-ray data, in order to constrain the parameters of their coronae. Using a phenomenological cut-off power-law model, with the inclusion of a reflection component, we derived rest-frame values of the high energy cut-off of $E_{cut}=106_{-37}^{+102}$ keV and $E_{cut}=66_{-12}^{+17}$ keV, respectively. Comptonization models consistently give as best-fit parameters electron temperatures of $\sim 45$ keV and $\sim 28$ keV, respectively, and optically thick coronae ($\tau >1$). These low coronal temperatures fall in the limited region allowed at these luminosities to avoid runaway pair production.

arXiv comment8 pages, 2 figures, accepted for publication in ApJ Letter

References in corpus (41)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• A Catalog of Quasar Properties from SDSS DR7
• Broad-band gamma-ray and X-ray spectra of NGC 4151 and their implications for physical processes and geometry
• Improved Reflection Models of Black-Hole Accretion Disks: Treating the Angular Distribution of X-rays
• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• The May 1989 outburst of the Soft X-ray Transient GS 2023+338 (V404 Cyg)
• The XMM-Newton view of PG quasars I. X-ray continuum and absorption
• A rapidly spinning supermassive black hole at the centre of NGC 1365
• Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei
• A global look at X-ray time lags in Seyfert Galaxies
• Compton reflection and iron fluorescence in BeppoSAX observations of Seyfert type 1 galaxies
• X-Ray and Optical Flux Ratio Anomalies in Quadruply Lensed Quasars: I. Zooming in on Quasar Emission Regions
• ON THE GEOMETRY OF THE X-RAY EMITTING REGION IN SEYFERT GALAXIES
• X-ray Reflection Spectroscopy of the Black Hole GX 339-4: Exploring the Hard State with Unprecedented Sensitivity
• Black Hole Mass Estimates Based on CIV are Consistent with Those Based on the Balmer Lines
• On the size and location of the X-ray emitting coronae around black holes
• BAT AGN Spectroscopic Survey -- XII. The relation between coronal properties of Active Galactic Nuclei and the Eddington ratio
• Seyfert galaxies in the local Universe (z$\le$ 0.1): the average X-ray spectrum as seen by $BeppoSAX$
• NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk
• Modelling the broad Fe Kα reverberation in the AGN NGC 4151
• Testing Comptonization models using BeppoSAX observations of Seyfert 1 galaxies
• The INTEGRAL high energy cut-off distribution of type 1 AGN
• X-ray properties of the Northern Galactic Cap AGNs in the 58-month Swift-BAT catalog
• Gravitational Lensing Size Scales for Quasars
• The hard X-ray spectrum of NGC 5506 as seen by NuSTAR
• Constraining the nature of High Frequency Peakers. I. The spectral variability
• A Consistent Picture Emerges: A Compact X-ray Continuum Emission Region in the Gravitationally Lensed Quasar SDSS J0924+0219
• The NuSTAR Extragalactic Surveys: X-ray spectroscopic analysis of the bright hard-band selected sample
• Broadband X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292
• Tracking the Iron K$\alpha$ line and the Ultra Fast Outflow in NGC 2992 at different accretion states
• MoCA: A Monte Carlo code for Comptonisation in Astrophysics. I. Description of the code and first results
• NuSTAR reveals the extreme properties of the super-Eddington accreting SMBH in PG 1247+267
• 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
• NuSTAR Hard X-ray View of Low-luminosity Active Galactic Nuclei: High-energy Cutoff and Truncated Thin Disk
• The NuSTAR Extragalactic Survey: Average broad-band X-ray spectral properties of the NuSTAR detected AGN
• In-flight PSF calibration of the NuSTAR hard X-ray optics
• Coronal temperatures of the AGN ESO 103-035 and IGR 2124.7+5058 from NuSTAR observations
• XMM-Newton reveals a Seyfert-like X-ray spectrum in the z=3.6 QSO B1422+231
• On the high energy cut-off of accreting sources: is GR relevant?
• Coronal properties of the luminous radio-quiet quasar QSO B2202$-$209

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