Compton-thick AGNs in the NuSTAR Era. III. A Systematic Study of the Torus Covering Factor

Marchesi, S.; Ajello, M.; Zhao, X.; Marcotulli, L.; Baloković, Mislav; Brightman, Murray; Comastri, A.; Cusumano, G.; Lanzuisi, G.; Parola, V. La; Segreto, A.; Vignali, C.

doi:10.3847/1538-4357/aafbeb

Cited by 48 publications

(59 citation statements)

References 67 publications

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“…The distribution of AGN as a function of luminosity and absorbing column density is given by the XLF. Marchesi et al (2019) studied the torus covering factor of 35 Compton-thick objects using NuSTAR spectra, finding an average covering factor 0.5, i.e., θ OA 60 • . For the Swift-BAT 70-month AGN sample, Ricci et al (2017) found that for the 12 objects for which the opening angle of the torus could be constrained, the median value was similar, θ OA is 58 ± 3 • .…”

Section: Modeling Agn Spectramentioning

confidence: 99%

Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background

Ananna

Treister

Urry³

et al. 2020

ApJ

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We constrain X-ray spectral shapes for the ensemble of AGN based on the shape of the Cosmic X-ray Background (CXB). Specifically, we rule out regions of X-ray spectral parameter space that do not reproduce the CXB in the energy range 1−100 keV. The key X-ray spectral parameters are the photon index, Γ; the cutoff energy, E cutoff ; and the reflection scaling factor, R. Assuming each parameter follows a Gaussian distribution, we first explore the parameter space using a Bayesian approach and a fixed X-ray luminosity function (XLF). For σ E = 36 keV and σ R = 0.14, fixed at the observed values from the Swift-BAT 70-month sample, we allow R , E cutoff and Γ to vary subject to reproducing the CXB. We report results for σ Γ = 0.1 − 0.5. In an alternative approach, we define the parameter distributions, then forward model to fit the CXB by perturbing the XLF using a neural network. This approach allows us to rule out parameter combinations that cannot reproduce the CXB for any XLF. The marginalized conditional probabilities for the four free parameters are: R = 0.99 +0.11 −0.26 , E cutoff = 118 +24 −23 , σ Γ = 0.101 +0.097 −0.001 and Γ = 1.9 +0.08 −0.09 . We provide an interactive online tool for users to explore any combination of E cutoff , σ E , Γ , σ Γ , R and σ R , including different distributions for each absorption bin, subject to the integral CXB constraint. The distributions observed in many AGN samples can be ruled out by our analysis, meaning these samples can not be representative of the full AGN population. The few samples that fall within the acceptable parameter space are hard X-ray-selected, commensurate with their having fewer selection biases.

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Section: Modeling Agn Spectramentioning

confidence: 99%

Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background

Ananna

Treister

Urry³

et al. 2020

ApJ

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“…MYTorus, based on Monte Carlo simulations, self-consistently includes reflection and transmission (see e.g. Lanzuisi, et al 2015b for further details, Appendix B of Lanzuisi et al 2015a for a comparison with other models applied to heavily obscured AGN, and the recent work by Marchesi et al 2019). Additional components (low-energy scattering, host galaxy emission, and emission lines, as observed in particular in the X-ray spectrum of NGC1194) were included along with MYTorus.…”

Section: Spectral Modelingmentioning

confidence: 99%

Broad-band X-ray analysis of local mid-infrared-selected Compton-thick AGN candidates

Caria

Vignali

Lanzuisi³

et al. 2019

Monthly Notices of the Royal Astronomical Society

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The estimate of the number and space density of obscured AGN over cosmic time still represents an open issue. While the obscured AGN population is a key ingredient of the X-ray background synthesis models and is needed to reproduce its shape, a complete census of obscured AGN is still missing. Here we test the selection of obscured sources among the local 12µm sample of Seyfert galaxies. Our selection is based on a difference up to three orders of magnitude in the ratio between the AGN bolometric luminosity, derived from the spectral energy distribution (SED) decomposition, and the same quantity obtained by the published XMM-Newton 2-10 keV luminosity (L AGN bol (IR)/L AGN bol (X)). The selected sources are UGC05101, NGC1194 and NGC3079 for which the available X-ray wide bandpass, from Chandra and XMM-Newton plus NuSTAR data, extending to energies up to ∼30-45 keV, allows us an accurate determination of the column density, and hence of the true intrinsic power. The newly derived N H values clearly indicate heavy obscuration (∼ 1.2, 2.1 and 2.4 × 10 24 cm −2 for UGC05101, NGC1194 and NGC3079, respectively), and are consistent with the prominent silicate absorption feature observed in the Spitzer -IRS spectra of these sources (9.7µm rest frame). We finally checked that the resulting X-ray luminosities in the 2-10 keV band are in good agreement with those derived from the mid-IR band through empirical L MIR − L X relations.

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“…In Marchesi et al (2018Marchesi et al ( , 2019, M18, M19 hereafter) we analyzed the combined 2-100 keV spectra of 35 candidate nearby (average redshift z =0.03) CT-AGN, i.e., all the 100-month BAT candidate CT-AGN having archival NuSTAR data. 2-10 keV data have been obtained using archival XMM-Newton, Chandra and Swift-XRT data.…”

Section: Introductionmentioning

confidence: 99%

Compton-thick AGNs in the NuSTAR Era. V. Joint NuSTAR and XMM-Newton Spectral Analysis of Three “Soft-gamma” Candidate CT-AGNs in the Swift/BAT 100-month Catalog

Marchesi

Ajello

Zhao

et al. 2019

ApJ

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We present the joint NuSTAR and XMM-Newton spectral analysis in the 0.6-70 keV band of three candidate Compton thick (CT-) AGN selected in the 100-month Swift-BAT catalog. These objects were previously classified as CT-AGNs based on low quality Swift-XRT and Swift-BAT data, and had soft photon indices (Γ>2.2) that suggested a potential overestimation of the line of sight column density (N H,l.o.s. ). Thanks to the high-quality NuSTAR and XMM-Newton data we were able to determine that in all three objects the photon index was significantly overestimated, and two out of three sources are reclassified from CT to Compton thin, confirming a previously observed trend, i.e., that a significant fraction of BAT-selected, candidate CT-AGNs with poor soft X-ray data are reclassified as Compton thin when the NuSTAR data are added to the fit. Finally, thanks to both the good XMM-Newton spatial resolution and the high NuSTAR and XMM-Newton spectral quality, we found that the third object in our sample was associated to the wrong counterpart: the correct one, 2MASX J10331570+5252182, has redshift z=0.14036, which makes it one of the very few candidate CT-AGNs in the 100-month BAT catalog detected at z>0.1, and a rare CT quasar.

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Compton-thick AGNs in the NuSTAR Era. III. A Systematic Study of the Torus Covering Factor

Abstract: We present the analysis of a sample of 35 candidate Compton thick (CT-) active galactic nuclei (AGNs) selected in the nearby Universe (average redshift z ∼0.

Cited by 48 publications

References 67 publications

Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background

Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background

Broad-band X-ray analysis of local mid-infrared-selected Compton-thick AGN candidates

Compton-thick AGNs in the NuSTAR Era. V. Joint NuSTAR and XMM-Newton Spectral Analysis of Three “Soft-gamma” Candidate CT-AGNs in the Swift/BAT 100-month Catalog

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