The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL

Ursini, F.; Bassani, L.; Malizia, A.; Bazzano, A.; Bird, A. J.; Stephen, J. B.; Ubertini, P.

doi:10.1051/0004-6361/201936273

Cited by 11 publications

(11 citation statements)

References 83 publications

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“…This research has made use of the NuSTAR Data Analysis Software (2017) is not strongly inconsistent with our analysis, we confirm that our lower NuSTAR-based constraint is robust despite achieving no improvement in terms of χ 2 reduction with respect to modeling presented in PaperI. Using INTEGRAL data and two epochs of NuSTAR data in the hard X-ray band, Ursini et al (2019) affirm our result, surpassing an earlier lower limit (>210 keV) found by Marinucci et al (2015).…”

supporting

confidence: 85%

“…NGC 4388.-For this target our constraint agrees very well with a more detailed study by Ursini et al (2019), including NuSTAR and INTEGRAL hard X-ray data. We also confirm E cut ≈ 200 keV from a dedicated multiepoch study with a different spectral model (M. Baloković et al 2020, in preparation).…”

supporting

confidence: 84%

“…E cut has been well constrained using NuSTAR data in only a handful of obscured AGNs thus far: NGC 4945 (Puccetti et al 2014), MCG -05-23-016 (Baloković et al 2015), ESO 103-G035 (Buisson et al 2018), Mrk 1498 (Ursini et al 2018a), NGC 262, NGC 2992, NGC 7172 (Rani et al 2019), NGC 2110, and NGC 4388 (Ursini et al 2019). Additionally, lower limits on E cut based on NuSTAR data have been derived for obscured sources NGC 5506 (Matt et al 2015), Cyg A (Reynolds et al 2015), Cen A (Fürst et al 2016), PKS 2331-240, and PKS 2356-61 (Ursini et al 2018a).…”

Section: Introductionmentioning

confidence: 99%

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NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei. II. Median High-energy Cutoff in Seyfert II Hard X-Ray Spectra

Baloković

Harrison

Madejski

et al. 2020

ApJ

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Broadband X-ray spectroscopy of the X-ray emission produced in the coronae of active galactic nuclei (AGNs) can provide important insights into the physical conditions very close to their central supermassive black holes. The temperature of the Comptonizing plasma that forms the corona is manifested through a high-energy cutoff that has been difficult to directly constrain even in the brightest AGN because it requires high-quality data at energies above 10 keV. In this paper we present a large collection of coronal cutoff constraints for obscured AGNs based on a sample of 130AGNs selected in the hard X-ray band with Swift/BAT and observed nearly simultaneously with NuSTAR and Swift/XRT. We find that under a reasonable set of assumptions regarding partial constraints the median cutoff is well constrained to 290±20 keV, where the uncertainty is statistical and given at the 68% confidence level. We investigate the sensitivity of this result to our assumptions and find that consideration of various known systematic uncertainties robustly places the median cutoff between 240 and 340 keV. The central 68% of the intrinsic cutoff distribution is found to be between about 140 and 500 keV, with estimated uncertainties of 20 and 100 keV, respectively. In comparison with the literature, we find no clear evidence that the cutoffs in obscured and unobscured AGNs are substantially different. Our analysis highlights the importance of carefully considering partial and potentially degenerate constraints on the coronal high-energy cutoff in AGNs.Unified Astronomy Thesaurus concepts: Active galactic nuclei (16); X-ray active galactic nuclei (2035); Seyfert galaxies (1447); High energy astrophysics (739); X-ray surveys (1824)

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supporting

confidence: 85%

supporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

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NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei. II. Median High-energy Cutoff in Seyfert II Hard X-Ray Spectra

Baloković

Harrison

Madejski

et al. 2020

ApJ

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“…We used the results of Petrucci et al (2018), who fitted the XMM-Newton/pn data with nthcomp, also assuming a coronal temperature of 100 keV. The optical depths computed by the code are in the range 0.5-2, consistent with values commonly measured applying Comptonization models in spherical geometry (Tortosa et al 2018; see also Ursini et al 2019).…”

Section: Input Physical Parameterssupporting

confidence: 52%

Estimating the size of X-ray lamppost coronae in active galactic nuclei

Ursini

Dovčiak

Zhang

et al. 2020

A&A

Self Cite

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Aims. We report estimates of the X-ray coronal size of active galactic nuclei in the lamppost geometry. In this commonly adopted scenario, the corona is assumed for simplicity to be a point-like X-ray source located on the axis of the accretion disc. However, the corona must intercept a number of optical/UV seed photons from the disc consistent with the observed X-ray flux, which constrains its size. Methods. We employ a relativistic ray-tracing code, originally developed by Dovčiak and Done, that calculates the size of a Comptonizing lamppost corona illuminated by a standard thin disc. We assume that the disc extends down to the innermost stable circular orbit of a non-spinning or a maximally spinning black hole. We apply this method to a sample of 20 Seyfert 1 galaxies using simultaneous optical/UV and X-ray archival data from XMM-Newton. Results. At least for the sources accreting below the Eddington limit, we find that a Comptonizing lamppost corona can generally exist, but with constraints on its size and height above the event horizon of the black hole depending on the spin. For a maximally spinning black hole, a solution can almost always be found at any height, while for a non-spinning black hole the height must generally be higher than 5 gravitational radii. This is because, for a given luminosity, a higher spin implies more seed photons illuminating the corona, which is due to a larger and hotter inner disc area. The maximal spin solution is favoured, as it predicts an X-ray photon index in better agreement with the observations.

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“…The ionization parameter log ξ/ erg cm s −1 = 0.1 +0.1 −0.1 , and covering fraction found in our work, 0.21 +0.01 −0.01 , is consistent with Lubiński et al (2016). Current measurements of cutoff energies of the primary power-law component, range between 50 and 300 keV (Tortosa et al 2018;Molina et al 2019;Ursini et al 2019) for bright Seyfert 1 galaxies and require spectra extending well above 50 keV for better constraints. Using relativistic reflection model, we found a lower limit to the cutoff energy, Ec > 276 keV.…”

Section: Resultssupporting

confidence: 87%

A broadband X-ray spectral study of the Seyfert 1 galaxy ESO 141--G055 with XMM-Newton and NuSTAR

Ghosh,

Laha

2020

Preprint

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We have extensively studied the broadband X-ray spectra of the source ESO 141-G055 using all available XMM-Newton and NuSTAR observations. We detect a prominent soft excess below 2 keV, a narrow Fe line and a Compton hump (> 10 keV). The origin of the soft excess is still debated. We used two models to describe the soft excess: the blurred reflection from the ionized accretion disk and the intrinsic thermal Comptonisation model. We find that both of these models explain the soft excess equally well. We confirm that we do not detect any broad Fe line in the X-ray spectra of this source, although both the physical models prefer a maximally spinning black hole scenario (a>0.96). This may mean that either the broad Fe line is absent or blurred beyond detection. The Eddington rate of the source is estimated to be λ Edd ∼ 0.31. In the reflection model, the Compton hump has a contribution from both ionized and neutral reflection components. The neutral reflector which simultaneously describes the narrow Fe Kα and the Compton hump has a column density of N H 7 × 10 24 cm −2 . In addition, we detect a partially covering ionized absorption with ionization parameter log ξ/ erg cm s −1 = 0.1 +0.1 −0.1 and column density N H = 20.6 +1.0 −1.0 × 10 22 cm −2 with a covering factor of 0.21 +0.01 −0.01 .

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The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL

Cited by 11 publications

References 83 publications

NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei. II. Median High-energy Cutoff in Seyfert II Hard X-Ray Spectra

NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei. II. Median High-energy Cutoff in Seyfert II Hard X-Ray Spectra

Estimating the size of X-ray lamppost coronae in active galactic nuclei

A broadband X-ray spectral study of the Seyfert 1 galaxy ESO 141--G055 with XMM-Newton and NuSTAR

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