The Chandra deep field South/GOODS survey -: Optically faint X-ray sources

被引:54
作者
Mainieri, V
Rosati, P
Tozzi, P
Bergeron, J
Gilli, R
Hasinger, G
Nonino, M
Lehmann, I
Alexander, DM
Idzi, R
Koekemoer, AM
Norman, C
Szokoly, G
Zheng, W
机构
[1] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany
[2] European So Observ, D-85748 Garching, Germany
[3] Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy
[4] Osserv Astron Trieste, INAF, I-34131 Trieste, Italy
[5] Inst Astrophys, F-75014 Paris, France
[6] Osserv Astrofis Arcetri, INAF, I-50125 Florence, Italy
[7] Inst Astron, Cambridge CB3 0HA, England
[8] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[9] Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, Baltimore, MD 21218 USA
关键词
surveys; galaxies : active; galaxies : quasars : general; cosmology : diffuse radiation; X-ray : galaxies; X-rays : general;
D O I
10.1051/0004-6361:20041212
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We provide important new constraints on the nature and redshift distribution of optically faint ( R >= 25) X- ray sources in the Chandra Deep Field South Survey. We use a large multi- wavelength data set, including the GOODS/ ACS survey, the recently released Hubble Ultra Deep Field ( UDF) data, and the new public VLT/ ISAAC imaging. We show that we can derive accurate photometric redshifts for the spectroscopically unidentified sources thus maximizing the redshift completeness for the whole X- ray sample. Our new redshift distribution for the X- ray source population is in better agreement with that predicted by X- ray background synthesis models; however, we still find an overdensity of low redshift ( z < 1) sources. The optically faint sources are mainly X- ray absorbed AGN, as determined from direct X- ray spectral analysis and other diagnostics. Many of these optically faint sources have high (> 10) X- ray- to- optical flux ratios. We also find that similar to 71% of them are well fitted with the SED of an early- type galaxy with < z(phot)> similar to 1.9 and the remaining 29% with irregular or starburst galaxies mainly at z(phot) > 3. We estimate that 15% of the optically faint sources are X- ray absorbed QSOs. The overall population of X- ray absorbed QSOs contributes a similar to 11% fraction of the [ 2 - 10] keV X- ray Background ( XRB) whereas current XRB synthesis models predict a similar to 38% contribution.
引用
收藏
页码:805 / 821
页数:17
相关论文
共 45 条
[1]   The Chandra deep field north survey.: VI.: The nature of the optically faint X-ray source population [J].
Alexander, DM ;
Brandt, WN ;
Hornschemeier, AE ;
Garmire, GP ;
Schneider, DP ;
Bauer, FE ;
Griffiths, RE .
ASTRONOMICAL JOURNAL, 2001, 122 (05) :2156-2176
[2]   The Chandra Deep Field North survey. XIII. 2 Ms point-source catalogs [J].
Alexander, DM ;
Bauer, FE ;
Brandt, WN ;
Schneider, DP ;
Hornschemeier, AE ;
Vignali, C ;
Barger, AJ ;
Broos, PS ;
Cowie, LL ;
Garmire, GP ;
Townsley, LK ;
Bautz, MW ;
Chartas, G ;
Sargent, WLW .
ASTRONOMICAL JOURNAL, 2003, 126 (02) :539-574
[3]   The Chandra Deep Field North Survey. X. X-ray emission from very red objects [J].
Alexander, DM ;
Vignali, C ;
Bauer, FE ;
Brandt, WN ;
Hornschemeier, AE ;
Garmire, GP ;
Schneider, DP .
ASTRONOMICAL JOURNAL, 2002, 123 (03) :1149-1162
[4]   Optical and infrared properties of the 2 Ms Chandra Deep Field North X-ray sources [J].
Barger, AJ ;
Cowie, LL ;
Capak, P ;
Alexander, DM ;
Bauer, FE ;
Fernandez, E ;
Brandt, WN ;
Garmire, GP ;
Hornschemeier, AE .
ASTRONOMICAL JOURNAL, 2003, 126 (02) :632-665
[5]   Constraints on the early formation of field elliptical galaxies [J].
Barger, AJ ;
Cowie, LL ;
Trentham, N ;
Fulton, E ;
Hu, EM ;
Songaila, A ;
Hall, D .
ASTRONOMICAL JOURNAL, 1999, 117 (01) :102-110
[6]  
BENITEZ N, 2000, APJ, V536, P2000
[7]   SExtractor: Software for source extraction [J].
Bertin, E ;
Arnouts, S .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 117 (02) :393-404
[8]   The Chandra Deep Field North survey. V. 1 Ms source catalogs [J].
Brandt, WN ;
Alexander, DM ;
Hornschemeier, AE ;
Garmire, GP ;
Schneider, DP ;
Barger, AJ ;
Bauer, FE ;
Broos, PS ;
Cowie, LL ;
Townsley, LK ;
Burrows, CN ;
Chartas, G ;
Feigelson, ED ;
Griffiths, RE ;
Nousek, JA ;
Sargent, WLW .
ASTRONOMICAL JOURNAL, 2001, 122 (06) :2810-2832
[9]   COLORS AND MAGNITUDES PREDICTED FOR HIGH REDSHIFT GALAXIES [J].
COLEMAN, GD ;
WU, CC ;
WEEDMAN, DW .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1980, 43 (03) :393-416
[10]   The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton [J].
De Luca, A ;
Molendi, S .
ASTRONOMY & ASTROPHYSICS, 2004, 419 (03) :837-848