Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/34540
Title: | X-ray properties and obscured fraction of AGN in the J1030 Chandra field | Authors: | SIGNORINI, Matilde MARCHESI, STEFANO GILLI, Roberto Brusa, Marcella COMASTRI, Andrea D'AMATO, Quirino Iwasawa, Kazushi LANZUISI, Giorgio MAZZOLARI, Giovanni MIGNOLI, Marco PECA, ALESSANDRO PRANDONI, ISABELLA TOZZI, Paolo VIGNALI, CRISTIAN VITO, Fabio Norman, Colin |
Issue Date: | 2023 | Journal: | ASTRONOMY & ASTROPHYSICS | Number: | 676 | First Page: | A49 | Abstract: | The 500ks Chandra ACIS-I observation of the field around the $z=6.31$ quasar SDSS J1030+0524 is currently the 5th deepest extragalactic X-ray survey. The rich multi-band coverage of the field allowed for an effective identification and redshift determination of the X-ray source counterparts: to date a catalog of 243 extragalactic X-ray sources with either a spectroscopic or photometric redshift estimate in the range $z\approx0-6$ is available over a 355 arcmin$^2$ area. Given its depth and the multi-band information, this catalog is an excellent resource to investigate X-ray spectral properties of distant Active Galactic Nuclei (AGN) and derive the redshift evolution of their obscuration. We performed a thorough X-ray spectral analysis for each object in the sample, measuring its nuclear column density $N_{\rm H}$ and intrinsic (de-absorbed) 2-10 keV rest-frame luminosity, $L_{2-10}$. Whenever possible, we also used the presence of the Fe K$_\alpha$ emission line to improve the photometric redshift estimates. We measured the fractions of AGN hidden by column densities in excess of $10^{22}$ and $10^{23}$cm$^{-2}$ ($f_{22}$ and $f_{23}$, respectively) as a function of $L_{2-10}$ and redshift, and corrected for selection effects to recover the intrinsic obscured fractions. At $z\sim 1.2$, we found $f_{22}\sim0.7-0.8$ and $f_{23}\sim0.5-0.6$, respectively, in broad agreement with the results from other X-ray surveys. No significant variations with X-ray luminosity were found within the limited luminosity range probed by our sample (log$L_{2-10}\sim 42.8-44.3$). When focusing on luminous AGN with log$L_{2-10}\sim44$ to maximize the sample completeness up to large cosmological distances, we did not observe any significant change in $f_{22}$ or $f_{23}$ over the redshift range $z\sim0.8-3$. Nonetheless, the obscured fractions we measure are significantly higher than ... | URI: | http://hdl.handle.net/20.500.12386/34540 | URL: | https://www.aanda.org/articles/aa/full_html/2023/08/aa46364-23/aa46364-23.html http://arxiv.org/abs/2305.13368v1 https://ui.adsabs.harvard.edu/abs/2023A%26A...676A..49S/abstract |
ISSN: | 0004-6361 | DOI: | 10.1051/0004-6361/202346364 | Bibcode ADS: | 2023A&A...676A..49S | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
aa46364-23.pdf | Pdf editoriale | 5.94 MB | Adobe PDF | View/Open |
Page view(s)
12
checked on Apr 27, 2024
Download(s)
5
checked on Apr 27, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.