TY - JOUR
T1 - AGN populations in large-volume X-ray surveys
T2 - Photometric redshifts and population types found in the stripe 82X survey
AU - Ananna, Tonima Tasnim
AU - Salvato, Mara
AU - Lamassa, Stephanie
AU - Urry, C. Megan
AU - Cappelluti, Nico
AU - Cardamone, Carolin
AU - Civano, Francesca
AU - Farrah, Duncan
AU - Gilfanov, Marat
AU - Glikman, Eilat
AU - Hamilton, Mark
AU - Kirkpatrick, Allison
AU - Lanzuisi, Giorgio
AU - Marchesi, Stefano
AU - Merloni, Andrea
AU - Nandra, Kirpal
AU - Natarajan, Priyamvada
AU - Richards, Gordon T.
AU - Timlin, John
N1 - Funding Information:
TA wishes to thank her parents, M. A. Quayum and Shamim Ara Begum, and her husband, Mehrab Bakhtiar, for their constant support under all conditions. She is very grateful to Ms. Birgit Boller of Max Planck, Garching, for supporting her visit there. The authors thank Ms. Geriana Van Atta of Yale University. This project was supported by Yale University, and the XMM-Newton analysis was partially supported by NASA grant NNX15AJ40G.
Publisher Copyright:
© 2017. The American Astronomical Society.
PY - 2017/11/20
Y1 - 2017/11/20
N2 - Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, σnmad = 0.06, and an outlier fraction, η = 13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).
AB - Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, σnmad = 0.06, and an outlier fraction, η = 13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).
KW - Catalogs
KW - Quasars: absorption lines
KW - Quasars: emission lines
KW - Quasars: general
KW - Techniques: photometric
KW - Techniques: spectroscopic
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U2 - 10.3847/1538-4357/aa937d
DO - 10.3847/1538-4357/aa937d
M3 - Article
AN - SCOPUS:85035010189
VL - 850
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 66
ER -