TY - JOUR
T1 - The XMM deep survey in the CDFS
T2 - XI. X-ray spectral properties of 185 bright sources
AU - Iwasawa, K.
AU - Comastri, A.
AU - Vignali, C.
AU - Gilli, R.
AU - Lanzuisi, G.
AU - Brandt, W. N.
AU - Tozzi, P.
AU - Brusa, M.
AU - Carrera, F. J.
AU - Ranalli, P.
AU - Mainieri, V.
AU - Georgantopoulos, I.
AU - Puccetti, S.
AU - Paolillo, M.
N1 - Publisher Copyright:
© ESO 2020.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - We present the X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South with the three EPIC cameras combined. The 2-10 keV flux limit of the sample is 2? ×? 10-15 erg s-1 cm-2. The sources are distributed over a redshift range of z? =? 0.1-3.8, with 11 new X-ray redshift measurements included. A spectral analysis was performed using a simple model to obtain absorbing column densities, rest-frame 2-10 keV luminosities, and Fe K line properties of 180 sources at z? > ? 0.4. Obscured AGN are found to be more abundant toward higher redshifts. Using the XMM-Newton data alone, seven Compton-thick AGN candidates were identified, which set the Compton-thick AGN fraction at ≂ 4%. An exploratory spectral inspection method with two rest-frame X-ray colours and an Fe line strength indicator was introduced and tested against the results from spectral fitting. This method works reasonably well to characterise a spectral shape and can be useful for a pre-selection of Compton-thick AGN candidates. We found six objects exhibiting broad Fe K lines out of 21 unobscured AGN of best data quality, implying a detection rate of ∼30%. Five redshift spikes, each with more than six sources, are identified in the redshift distribution of the X-ray sources. Contrary to the overall trend, the sources at the two higher redshift spikes, at z = 1.61 and z = 2.57, exhibit a puzzlingly low obscuration.
AB - We present the X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South with the three EPIC cameras combined. The 2-10 keV flux limit of the sample is 2? ×? 10-15 erg s-1 cm-2. The sources are distributed over a redshift range of z? =? 0.1-3.8, with 11 new X-ray redshift measurements included. A spectral analysis was performed using a simple model to obtain absorbing column densities, rest-frame 2-10 keV luminosities, and Fe K line properties of 180 sources at z? > ? 0.4. Obscured AGN are found to be more abundant toward higher redshifts. Using the XMM-Newton data alone, seven Compton-thick AGN candidates were identified, which set the Compton-thick AGN fraction at ≂ 4%. An exploratory spectral inspection method with two rest-frame X-ray colours and an Fe line strength indicator was introduced and tested against the results from spectral fitting. This method works reasonably well to characterise a spectral shape and can be useful for a pre-selection of Compton-thick AGN candidates. We found six objects exhibiting broad Fe K lines out of 21 unobscured AGN of best data quality, implying a detection rate of ∼30%. Five redshift spikes, each with more than six sources, are identified in the redshift distribution of the X-ray sources. Contrary to the overall trend, the sources at the two higher redshift spikes, at z = 1.61 and z = 2.57, exhibit a puzzlingly low obscuration.
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U2 - 10.1051/0004-6361/201937246
DO - 10.1051/0004-6361/201937246
M3 - Review article
AN - SCOPUS:85088290534
SN - 0004-6361
VL - 639
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A51
ER -