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Title: X-Ray Spectral Properties of Seven Heavily Obscured Seyfert 2 Galaxies

Abstract

We present the combined Chandra and Swift -BAT spectral analysis of seven Seyfert 2 galaxies selected from the Swift -BAT 100 month catalog. We selected nearby ( z ≤ 0.03) sources lacking a ROSAT counterpart that never previously been observed with Chandra in the 0.3–10 keV energy range, and targeted these objects with 10 ks Chandra ACIS-S observations. The X-ray spectral fitting over the 0.3–150 keV energy range allows us to determine that all the objects are significantly obscured, with N{sub H} ≥ 10{sup 23} cm{sup −2} at a >99% confidence level. Moreover, one to three sources are candidate Compton-thick Active Galactic Nuclei (CT-AGNs; i.e., N{sub H}≥10{sup 24} cm{sup −2}). We also test the recent spectral curvature method developed by Koss et al. to find candidate CT-AGNs, finding a good agreement between our results and their predictions. Because the selection criteria we adopted were effective in detecting highly obscured AGNs, further observations of these and other Seyfert 2 galaxies selected from the Swift -BAT 100 month catalog will allow us to create a statistically significant sample of highly obscured AGNs, therefore providing a better understanding of the physics of the obscuration processes.

Authors:
;  [1];  [2]; ; ;  [3]
  1. Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)
  2. INAF—Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)
  3. INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy)
Publication Date:
OSTI Identifier:
22663810
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 836; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CATALOGS; COMPUTERIZED TOMOGRAPHY; FORECASTING; GALAXY NUCLEI; KEV RANGE; X RADIATION; X-RAY GALAXIES

Citation Formats

Marchesi, S., Ajello, M., Comastri, A., Cusumano, G., Parola, V. La, and Segreto, A., E-mail: smarche@clemson.edu. X-Ray Spectral Properties of Seven Heavily Obscured Seyfert 2 Galaxies. United States: N. p., 2017. Web. doi:10.3847/1538-4357/836/1/116.
Marchesi, S., Ajello, M., Comastri, A., Cusumano, G., Parola, V. La, & Segreto, A., E-mail: smarche@clemson.edu. X-Ray Spectral Properties of Seven Heavily Obscured Seyfert 2 Galaxies. United States. doi:10.3847/1538-4357/836/1/116.
Marchesi, S., Ajello, M., Comastri, A., Cusumano, G., Parola, V. La, and Segreto, A., E-mail: smarche@clemson.edu. Fri . "X-Ray Spectral Properties of Seven Heavily Obscured Seyfert 2 Galaxies". United States. doi:10.3847/1538-4357/836/1/116.
@article{osti_22663810,
title = {X-Ray Spectral Properties of Seven Heavily Obscured Seyfert 2 Galaxies},
author = {Marchesi, S. and Ajello, M. and Comastri, A. and Cusumano, G. and Parola, V. La and Segreto, A., E-mail: smarche@clemson.edu},
abstractNote = {We present the combined Chandra and Swift -BAT spectral analysis of seven Seyfert 2 galaxies selected from the Swift -BAT 100 month catalog. We selected nearby ( z ≤ 0.03) sources lacking a ROSAT counterpart that never previously been observed with Chandra in the 0.3–10 keV energy range, and targeted these objects with 10 ks Chandra ACIS-S observations. The X-ray spectral fitting over the 0.3–150 keV energy range allows us to determine that all the objects are significantly obscured, with N{sub H} ≥ 10{sup 23} cm{sup −2} at a >99% confidence level. Moreover, one to three sources are candidate Compton-thick Active Galactic Nuclei (CT-AGNs; i.e., N{sub H}≥10{sup 24} cm{sup −2}). We also test the recent spectral curvature method developed by Koss et al. to find candidate CT-AGNs, finding a good agreement between our results and their predictions. Because the selection criteria we adopted were effective in detecting highly obscured AGNs, further observations of these and other Seyfert 2 galaxies selected from the Swift -BAT 100 month catalog will allow us to create a statistically significant sample of highly obscured AGNs, therefore providing a better understanding of the physics of the obscuration processes.},
doi = {10.3847/1538-4357/836/1/116},
journal = {Astrophysical Journal},
number = 1,
volume = 836,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}