We present the 2-100 keV spectral analysis of 30 candidate Compton-thick-(CT-)active galactic nuclei (AGNs) selected in the Swift-Burst Alert Telescope (BAT) 100 month survey. The average redshift of these objects is , and they all lie within â¼500 Mpc. We used the MyTorus model to perform X-ray spectral fittings both without and with the contribution of the Nuclear Spectroscopic Telescope Array (NuSTAR) data in the 3-50 keV energy range. When the NuSTAR data are added to the fit, 13 out of 30 of these objects (43% of the whole sample) have intrinsic absorption NH< 1024cm-2at the >3Ï confidence level, i.e., they are reclassified from Compton thick to Compton thin. Consequently, we infer an overall observed fraction of the CT-AGN, with respect to the whole AGN population, lower than the one reported in previous works, as low as â¼4%. We find evidence that this overestimation of NHis likely due to the low quality of a subsample of spectra, either in the 2-10 keV band or in the Swift-BAT one.
Marchesi, S., Ajello, M., Marcotulli, L., Comastri, A., Lanzuisi, G., Vignali, C. (2018). Compton-thick AGNs in the NuSTAR Era. THE ASTROPHYSICAL JOURNAL, 854(1), 49-64 [10.3847/1538-4357/aaa410].
Compton-thick AGNs in the NuSTAR Era
Marchesi, S.
Writing – Original Draft Preparation
;Lanzuisi, G.Membro del Collaboration Group
;Vignali, C.Membro del Collaboration Group
2018
Abstract
We present the 2-100 keV spectral analysis of 30 candidate Compton-thick-(CT-)active galactic nuclei (AGNs) selected in the Swift-Burst Alert Telescope (BAT) 100 month survey. The average redshift of these objects is , and they all lie within â¼500 Mpc. We used the MyTorus model to perform X-ray spectral fittings both without and with the contribution of the Nuclear Spectroscopic Telescope Array (NuSTAR) data in the 3-50 keV energy range. When the NuSTAR data are added to the fit, 13 out of 30 of these objects (43% of the whole sample) have intrinsic absorption NH< 1024cm-2at the >3Ï confidence level, i.e., they are reclassified from Compton thick to Compton thin. Consequently, we infer an overall observed fraction of the CT-AGN, with respect to the whole AGN population, lower than the one reported in previous works, as low as â¼4%. We find evidence that this overestimation of NHis likely due to the low quality of a subsample of spectra, either in the 2-10 keV band or in the Swift-BAT one.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
