The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources

Masayuki Akiyama; Yoshihiro Ueda; Mike G. Watson; Hisanori Furusawa; Tadafumi Takata; Chris Simpson; Tomoki Morokuma; Toru Yamada; Kouji Ohta; Fumihide Iwamuro; Kiyoto Yabe; Naoyuki Tamura; Yuuki Moritani; Naruhisa Takato; Masahiko Kimura; Toshinori Maihara; Gavin Dalton; Ian Lewis; Hanshin Lee; Emma Curtis Lake; Edward Macaulay; Frazer Clarke; John D. Silverman; Scott Croom; Masami Ouchi; Hitoshi Hanami; J. Diaz Tello; Tomohiro Yoshikawa; Naofumi Fujishiro; Kazuhiro Sekiguchi

doi:10.1093/pasj/psv050

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arXiv · 1505.05487

The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources

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Abstract

We report the multi-wavelength identification of the X-ray sources found in the Subaru-XMM-Newton Deep Survey (SXDS) using deep imaging data covering the wavelength range between the far-UV to the mid-IR. We select a primary counterpart of each X-ray source by applying the likelihood ratio method to R-band, 3.6micron, near-UV, and 24micron source catalogs as well as matching catalogs of AGN candidates selected in 1.4GHz radio and i'-band variability surveys. Once candidates of Galactic stars, ultra-luminous X-ray sources in a nearby galaxy, and clusters of galaxies are removed there are 896 AGN candidates in the sample. We conduct spectroscopic observations of the primary counterparts with multi-object spectrographs in the optical and NIR; 65\% of the X-ray AGN candidates are spectroscopically-identified. For the remaining X-ray AGN candidates, we evaluate their photometric redshift with photometric data in 15 bands. Utilising the multi-wavelength photometric data of the large sample of X-ray selected AGNs, we evaluate the stellar masses, M*, of the host galaxies of the narrow-line AGNs. The distribution of the stellar mass is remarkably constant from z=0.1 to 4.0. The relation between M* and 2--10 keV luminosity can be explained with strong cosmological evolution of the relationship between the black hole mass and M*. We also evaluate the scatter of the UV-MIR spectral energy distribution (SED) of the X-ray AGNs as a function of X-ray luminosity and absorption to the nucleus. The scatter is compared with galaxies which have redshift and stellar mass distribution matched with the X-ray AGN. The UV-NIR SEDs of obscured X-ray AGNs are similar to those of the galaxies in the matched sample. In the NIR-MIR range, the median SEDs of X-ray AGNs are redder, but the scatter of the SEDs of the X-ray AGN broadly overlaps that of the galaxies in the matched sample.

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Masayuki Akiyama, Yoshihiro Ueda, Mike G. Watson, Hisanori Furusawa, Tadafumi Takata, Chris Simpson, Tomoki Morokuma, Toru Yamada, Kouji Ohta, Fumihide Iwamuro, Kiyoto Yabe, Naoyuki Tamura, Yuuki Moritani, Naruhisa Takato, Masahiko Kimura, Toshinori Maihara, Gavin Dalton, Ian Lewis, Hanshin Lee, Emma Curtis Lake, Edward Macaulay, Frazer Clarke, John D. Silverman, Scott Croom, Masami Ouchi, Hitoshi Hanami, J. Diaz Tello, Tomohiro Yoshikawa, Naofumi Fujishiro, Kazuhiro Sekiguchi. 2015-05-13. The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources. https://doi.org/10.1093/pasj/psv050

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