J/ApJS/191/124 Optical spectroscopy of ECDF-S X-ray sources (Silverman+, 2010)
The Extended Chandra Deep Field-South survey: optical spectroscopy of faint
X-ray sources with the VLT and Keck.
Silverman J.D., Mainieri V., Salvato M., Hasinger G., Bergeron J.,
Capak P., Szokoly G., Finoguenov A., Gilli R., Rosati P., Tozzi P.,
Vignali C., Alexander D.M., Brandt W.N., Lehmer B.D., Luo B., Rafferty D.,
Xue Y.Q., Balestra I., Bauer F.E., Brusa M., Comastri A., Kartaltepe J.,
Koekemoer A.M., Miyaji T., Schneider D.P., Treister E., Wisotski L.,
Schramm M.
<Astrophys. J. Suppl. Ser., 191, 124-142 (2010)>
=2010ApJS..191..124S 2010ApJS..191..124S
ADC_Keywords: Active gal. nuclei ; Spectroscopy ; Redshifts ; X-ray sources ;
Photometry, RI ; Galaxies, optical
Keywords: galaxies: active - galaxies: Seyfert - quasars: general -
surveys - X-rays: galaxies
Abstract:
We present the results of a program to acquire high-quality optical
spectra of X-ray sources detected in the Extended-Chandra Deep
Field-South (E-CDF-S) and its central 2Ms area. New spectroscopic
redshifts, up to z=4, are measured for 283 counterparts to Chandra
sources with deep exposures (t∼2-9hr per pointing) using multi-slit
facilities on both VLT (VIMOS) and Keck (DEIMOS), thus bringing the
total number of spectroscopically identified X-ray sources to over 500
in this survey field. Since our new spectroscopic identifications are
mainly associated with X-ray sources in the shallower 250ks coverage,
we provide a comprehensive catalog of X-ray sources detected in the
E-CDF-S including the optical and near-infrared counterparts,
determined by a likelihood routine, and redshifts (both spectroscopic
and photometric), that incorporate published spectroscopic catalogs,
thus resulting in a final sample with a high fraction (80%) of X-ray
sources having secure identifications. Our redshift catalog includes
17 type-2 QSOs at 1≲z≲3.5. Based on our deepest (9 hr) VLT/VIMOS
observation, we identify "elusive" optically faint galaxies (Rmag∼25)
at z∼2-3 based upon the detection of interstellar absorption lines
(e.g., OII+SiIV, CII], CIV).
Description:
We have acquired optical spectra with the VLT, using the Visible
Multi-Object Spectrograph (VIMOS) in Oct-Dec 2004, Jan and Oct 2005,
Dec 2007 and Jan-Feb 2008. We have carried out two pointings, each
with two different setups, in the northern half of the E-CDF-S field.
Optical spectra were also obtained in January of 2007, 2008, and 2010
on Keck II with the Deep Imaging Multi-object Spectrograph (DEIMOS).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 87 701 Optical and near-infrared counterparts to X-ray
sources in the E-CDF-S
table7.dat 44 49 Redshifts for X-ray sources solely detected in
the 1-2Ms catalogs
table8.dat 46 51 Spectroscopic redshifts of VLA radio sources
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See also:
III/250 : The VIMOS VLT deep survey (VVDS-DEEP) (Le Fevre+ 2005)
J/A+A/512/A12 : VLT/VIMOS spectroscopy in GOODS-South field (Balestra+, 2010)
J/ApJ/693/1713 : Spectroscopy of X-ray sources in ECDF-S (Treister+, 2009)
J/ApJS/179/19 : CDFS survey: 2 Ms source catalogs (Luo+, 2008)
J/ApJS/179/71 : VLA survey of the CDF-S I. (Kellermann+, 2008)
J/ApJS/179/114 : VLA 1.4GHz survey of E-CDF-S (Miller+, 2008)
J/ApJS/179/95 : VLA survey of CDF-S. II. (Mainieri+, 2008)
J/A+A/478/83 : GOODS-South Field VLT/FORS2 redshifts. III. (Vanzella+, 2008)
J/A+A/465/1099 : Redshift catalog of 691 objects in CDFS (Ravikumar+, 2007)
J/A+A/454/423 : GOODS-South Field VLT/FORS2 redshifts. II. (Vanzella+, 2006)
J/A+A/437/883 : K20 survey: spectroscopic catalogue (Mignoli+, 2005)
J/ApJS/161/21 : Extended Chandra Deep Field-South survey (Lehmer+, 2005)
J/ApJS/155/271 : Chandra Deep Field-South: Optical spectroscopy (Szokoly+,
2004)
J/ApJS/139/369 : Chandra Deep Field South. 1 Ms catalog (Giacconi+, 2002)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- XID Lehmer et al., 2005 (Cat. J/ApJS/161/21)
number (<[LBA2005] NNN> in Simbad)
5- 12 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000) (1)
14- 22 F9.5 deg DEdeg Declination in decimal degrees (J2000) (1)
24- 30 A7 --- Cat Catalog associated with counterpart (2)
32- 34 F3.1 arcsec Sep Separation between X-ray and its counterpart
36- 40 F5.1 --- LR Likelihood ratio (3)
42- 45 F4.2 --- Rel Reliability for true counterpart (4)
47- 50 F4.1 mag Rmag ? R band AB magnitude
52- 56 F5.3 --- zsp ? Counterpart spectroscopic redshift
58- 60 F3.1 --- q_zsp ? Quality flag on zspec (5)
62- 63 I2 --- r_zsp ? Spectroscopic catalog (G2)
65- 69 A5 --- Class Spectroscopic classification (G1)
71- 75 F5.3 --- zph ? Photometric redshift (6)
77- 81 F5.3 --- e_zph ? Lower limit uncertainty in zphot
83- 87 F5.3 --- E_zph ? Upper limit uncertainty in zphot
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Note (1): Of the optical/near-infrared counterpart.
Note (2): Catalogs associated are:
ACS-z = GOODS-z or GEMS-z; z-band HST/ACS catalog;
WFI-R = WFI R-band catalog;
SOFI-H = H-band catalog from SOFI;
SOFI-K = K-band catalog from SOFI,
ISSAC-K = K-band catalog from VLT/ISAAC
Note (3): The likelihood ratio (LR; Equation (1)) is the probability that a
given optical or near-infrared source is the true counterpart to the
X-ray detection, relative to the chance that the same object is a
random background source. LR=(q(m)f(r))/n(m); see section 2 for
further details.
Note (4): Reliability (0<Rj<1; Sutherland & Saunders 1992) that a particular
source (j) is the true counterpart: Rj=LRj/ΣiLRi+(1-Q)
See section 2 for further details.
Note (5): Where "2" is secure, "1" for some uncertainty, "0" for no redshift.
A +0.5 if in agreement with photometric redshift.
Note (6): From Rafferty et al. (2010, in prep) and Luo et al. (2010,
Cat. J/ApJS/187/560).
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- XID Luo et al. 2008 (Cat. J/ApJS/179/19) number,
(<[LBB2008] NNN> in Simbad)
5- 12 F8.5 deg RAdeg Right Ascension of optical counterpart (J2000)
14- 22 F9.5 deg DEdeg Declination of optical counterpart (J2000)
24- 27 F4.1 mag Rmag R band AB magnitude
29- 33 F5.3 --- zsp Spectroscopic redshift
35 I1 --- q_zsp Quality of z: 1=some uncertainty, 2=secure.
37- 41 A5 --- Class Spectroscopic classification (G1)
43- 44 I2 --- r_zsp Spectroscopic origin (G2)
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- RID Radio identification number (1)
5- 12 F8.5 deg RAdeg Right Ascension of optical counterpart (J2000)
14- 22 F9.5 deg DEdeg Declination of optical counterpart (J2000)
24- 27 F4.1 mag Rmag R band AB magnitude
29- 33 F5.3 --- zsp Spectroscopic redshift
35 I1 --- q_zsp Quality of zsp: 1=some uncertainty, 2=secure.
37- 41 A5 --- Class Spectroscopic classification (G1)
43- 46 A4 --- Tel Origin of z (Keck or VLT)
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Note (1): Radio identification number from Kellermann et al., 2008
Cat. J/ApJS/179/71 and Miller et al., 2008, Cat. J/ApJS/179/114,
<[KFM2008] RID NNNA> in simbad.
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Globlal notes:
Note (G1): Class as follows:
BLAGN = Broad emission-line AGN. Presence of at least one emission line
having FWHM>2000km/s
NELG = Narrow emission-line galaxy. Presence of at least one emission line
having FWHM<2000km/s and no BLAGN signatures.
ALG = Absorption-line galaxy. No emission lines with an observed EQW>5Å.
Clear signs of absorption lines such as Ca H+K, MgII, or G band.
STAR = Star.
Note (G2): References as follows:
1 = Szokoly et al., 2004, Cat. J/ApJS/155/271;
2 = FORS2/GOODS (Vanzella et al., 2008, Cat. J/A+A/478/83);
3 = VVDS (Le Fevre et al., 2005, Cat. III/250);
5 = New VLT;
6 = VIMOS/GOODS (Balestra et al., 2010, Cat. J/A+A/512/A12);
10 = New Keck (2007-2008);
11 = Ravikumar et al., 2007, Cat. J/A+A/465/1099;
12 = New VLT/9hr;
13 = Treister et al. (2009, Cat. J/ApJ/693/1713);
14 = Wisotzki/Schramm, private communication;
15 = New Keck (2010).
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 29-Nov-2010