Relations between phenomenological and physical parameters in the hot coronae of AGNs computed with the MoCA code

Abstract

The primary X-ray emission in active galactic nuclei (AGNs) is widely believed to be due to Comptonisation of the thermal radiation from the accretion disc in a corona of hot electrons. The resulting spectra can, in first approximation, be modelled with a cut-off power law, the photon index and the high-energy roll-over encoding information on the physical properties of the X-ray-emitting region. The photon index and the high-energy curvature of AGNs ($\Gamma$, E${}_c$) have been largely studied since the launch of X-ray satellites operating above 10 keV. However, high-precision measurements of these two observables have only been obtained in recent years thanks to the unprecedented sensitivity of NuSTAR up to 79 keV. We aim at deriving relations between phenomenological parameters ($\Gamma$ and E${}_c$) and the intrinsic properties of the X-ray-emitting region (the hot corona), namely the optical depth and temperature. We use MoCA (Monte Carlo code for Comptonisation in Astrophysics) to produce synthetic spectra for the case of an AGN with M${}_{BH}$=1.5$\times$10${}^8$ M${}_{sun}$ and accretion rate of 10% and then compared them with the widely used power-law model with an exponential high-energy cutoff. We provide phenomenological relations relating $\Gamma$ and E${}_c$ with the opacity and temperature of the coronal electrons for the case of spherical and slab-like coronae. These relations give origin to a well defined parameter space which fully contains the observed values. Exploiting the increasing number of high-energy cut-offs quoted in the literature, we report on the comparison of physical quantities obtained using MoCA with those estimated using commonly adopted spectral Comptonisation models. Finally, we discuss the negligible impact of different black hole masses and accretion rates on the inferred relations.

arXiv commentAccepted for publication in A&A, 10 pages, 9 figures

References in corpus (51)

• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• Broad-band gamma-ray and X-ray spectra of NGC 4151 and their implications for physical processes and geometry
• X-ray reverberation around accreting black holes
• The Two-Phase Pair Corona Model for Active Galactic Nuclei and X-ray Binaries: How to Obtain Exact Solutions
• A Model for the X-Ray and UV Emission from Seyfert Galaxies and Galactic Black Holes
• Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei
• CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis
• Compton reflection and iron fluorescence in BeppoSAX observations of Seyfert type 1 galaxies
• X-ray Microlensing in RXJ1131-1231 and HE1104-1805
• The long term X-ray spectral variability of AGN
• X-ray absorption by Broad Line Region Clouds in Mrk 766
• BAT AGN Spectroscopic Survey -- XII. The relation between coronal properties of Active Galactic Nuclei and the Eddington ratio
• Radiative Processes in High Energy Astrophysics
• The NuSTAR spectrum of Mrk 335: Extreme relativistic effects within 2 gravitational radii of the event horizon?
• Testing Comptonization models using BeppoSAX observations of Seyfert 1 galaxies
• Properties of AGN coronae in the NuSTAR era II: hybrid plasma
• Further Evidence that Quasar X-Ray Emitting Regions Are Compact: X-Ray and Optical Microlensing in the Lensed Quasar Q J0158-4325
• A NuSTAR census of coronal parameters in Seyfert galaxies
• The broad band spectral variability of MCG-6-30-15 observed by NuSTAR and XMM-Newton
• Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the Narrow Line Seyfert 1 galaxy SWIFT J2127.4+5654
• A deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
• The INTEGRAL high energy cut-off distribution of type 1 AGN
• The high-Eddington NLS1 Ark 564 has the coolest corona
• The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation
• Testing Comptonizing coronae on a long BeppoSAX observation of the Seyfert 1 galaxy NGC 5548
• The INTEGRAL Complete Sample of Type 1 AGN
• INTEGRAL/IBIS Extragalactic survey: 20-100 keV selected AGN
• Hard X-ray spectra of AGN in the INTEGRAL complete sample
• The hard X-ray spectrum of NGC 5506 as seen by NuSTAR
• Coronal Properties of the Seyfert 1.9 Galaxy MCG -05-23-016 Determined from Hard X-ray Spectroscopy with NuSTAR
• NuSTAR Reveals the Comptonizing Corona of the Broad-Line Radio Galaxy 3C 382
• A Long Observation of NGC 5548 by BeppoSAX: the High Energy Cut-off, Intrinsic Spectral Variability and a Truly Warm Absorber
• Anatomy of the AGN in NGC 5548: III. The high-energy view with NuSTAR and INTEGRAL
• High-energy monitoring of NGC 4593 with XMM-Newton and NuSTAR. X-ray spectral analysis
• 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
• Multi-wavelength campaign on NGC 7469 IV. The broad-band X-ray spectrum
• 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
• The Seyfert 2 galaxy NGC 2110: hard X-ray emission observed by NuSTAR and variability of the iron K$\alpha$ line
• The rhythm of Fairall 9 -- I: Observing the spectral variability with XMM-Newton and NuSTAR
• NuSTAR Hard X-ray View of Low-luminosity Active Galactic Nuclei: High-energy Cutoff and Truncated Thin Disk
• Quasar spectral variability from the XMM-Newton serendipitous source catalogue
• Nustar Measurement Of Coronal Temperature In Two Luminous, High Redshift Qsos
• NuSTAR observations of Mrk 766: distinguishing reflection from absorption
• NuSTAR spectral analysis of two bright Seyfert 1 galaxies: MCG +8-11-11 and NGC 6814
• The complex iron line in NGC 7469 observed by BeppoSAX
• Study of X-ray variability and coronae of Seyfert galaxies using NuSTAR
• The absence of a thin disc in M81
• A deep X-ray view of the bare AGN Ark 120. VI. Geometry of the hot corona from spectroscopic and polarization signatures
• The NuSTAR view of the Seyfert Galaxy HE 0436-4717

Cited by in corpus (25)

• Spectral and temporal properties of Compton scattering by mildly relativistic thermal electrons
• NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
• Polarization constraints on the X-ray corona in Seyfert Galaxies: MCG-05-23-16
• The Nature of Soft Excess in ESO 362-G18 Revealed by XMM-Newton and NuSTAR Spectroscopy
• The soft excess of the NLS1 galaxy Mrk 359 studied with an XMM-Newton-NuSTAR monitoring campaign
• Probing the Origin of Changing-look Quasar Transitions with Chandra
• Fundamental X-ray Corona Parameters of Swift/BAT AGN
• The flaring X-ray corona in the quasar PDS 456
• Limits on X-ray Polarization at the Core of Centaurus A as Observed with the Imaging X-ray Polarimetry Explorer
• Investigating the interplay between the coronal properties and the hard X-ray variability of active galactic nuclei with NuSTAR
• The lively accretion disk in NGC 2992. II. The 2019/2021 X-ray monitoring campaigns
• Search for coronal temperature variation in Seyfert galaxies
• Coronal Properties of Low-Accreting AGNs using Swift, XMM-Newton and NuSTAR Observations
• An XMM-Newton study of active-inactive galaxy pairs
• NGC 3147: a prototypical low-luminosity active galactic nucleus with double-peaked optical and ultraviolet lines
• NuSTAR spectral analysis of three Seyfert galaxies: NGC 3227, NGC 5548 and MR 2251$-$178
• The X-ray emission of the Seyfert 2 galaxy MCG-01-24-12
• X-ray spectral and timing analysis of the Compton Thick Seyfert 2 galaxy NGC 1068
• Breaking the rules at $z\simeq$0.45: the rebel case of RBS 1055
• The first X-ray look at SMSS J114447.77-430859.3: the most luminous quasar in the last 9 Gyr
• Hard X-Ray broadband spectroscopy of Mrk 876: characterizing its spectrum
• Universality of coronal properties in accreting black holes across mass and accretion rate
• The SRG/eROSITA all-sky survey: Hard X-ray selected Active Galactic Nuclei
• X-ray polarization in radio-quiet AGN: Insights from the wedge corona model using Monte Carlo simulations
• Evidence for coronal temperature variation in Seyfert 2 ESO 103--035 using NuSTAR observations