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J/ApJ/679/1144    Galaxy clusters in LOS to background QSOs. I.   (Lopez+, 2008)

Galaxy clusters in the line of sight to background quasars. I. Survey design and incidence of Mg II absorbers at cluster redshifts. Lopez S., Barrientos L.F., Lira P., Padilla N., Gilbank D.G., Gladders M.D., Maza J., Tejos N., Vidal M., Yee H.K.C. <Astrophys. J., 679, 1144-1161 (2008)> =2008ApJ...679.1144L
ADC_Keywords: Clusters, galaxy ; QSOs ; Redshifts ; Equivalent widths Keywords: galaxies: clusters: general - quasars: absorption lines Abstract: We describe the first optical survey of absorption systems associated with cluster galaxies at z=0.3-0.9. We have cross-correlated quasars from the third data release of the SDSS (Cat. VII/243) with high-redshift cluster/group candidates from the Red-Sequence Cluster Survey (Cat. J/ApJS/157/1). We have found 442 quasar-cluster pairs for which the MgIIλ2796, 2803 doublet might be detected at a transverse (physical) distance d<2h-171Mpc from the cluster centers. To investigate the incidence dN/dz and equivalent width distribution n(W) of MgII systems at cluster redshifts, two statistical samples were drawn out of these pairs: one made of high-resolution spectroscopic quasar observations (46 pairs), and one made of quasars used in MgII searches found in the literature (375 pairs). Description: Low-resolution optical spectroscopic follow-up observations of the quasar candidates from the X-ray sample were carried out with the Wide Field Reimaging CCD Camera in long-slit grism mode on the du Pont telescope at Las Campanas Observatory on 2006 March 30 and September 15-16. High-resolution spectroscopy was obtained using the MIKE spectrograph on the Las Campanas Clay 6.5m telescope. We obtained 18 quasar spectra in three runs on 2006 March 18-19 and September 23-24 and 29-30 (see table 1). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 62 19 High-resolution spectroscopic quasar observations table2.dat 51 65 MgII absorber systems table3.dat 51 97 *Galaxy clusters
Note on table3.dat: This table displays only LOSs with detected absorption.
See also: VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010) J/ApJ/679/239 : Associated MgII absorbers (Vanden+, 2008) J/MNRAS/371/495 : Catalogue of 1806 MgII absorbers from SDSS DR3 (Bouche+, 2007) J/ApJ/639/766 : SDSS-DR3 strong MgII absorbers (Prochter+, 2006) J/ApJS/157/1 : Red-Sequence Cluster Survey (Gladders+, 2005) J/ApJS/158/161 : Photometric redshift catalog from the RCS (Hsieh+, 2005) J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004) : RCS2 home page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 18 A18 --- Name Quasar identification 20 A1 --- f_Name [b] Flag for newly discovered quasar; named after Chandra fields, no position given 22- 25 F4.1 mag gmag Magnitude in g-band 27- 31 I5 s ExpT Exposure time 33- 35 I3 --- S/N Median signal-to-noise ratio per pixel 37- 46 A10 "YYYY/MM/DD" Obs.Date Date of observation 47 A1 --- --- [-] 48- 49 I2 --- Date2 ? 2nd day of observation 51- 62 A12 --- Remark Data from archive
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 2 I2 --- LOS Line of sight number (G1) 4- 21 A18 --- Name Quasar identification 23- 26 F4.2 --- zem ? Emission redshift 28- 32 F5.3 --- zEW ? Minimum redshift (1) 34- 39 F6.4 --- zabs MgII absorption redshift 41- 45 F5.3 0.1nm W2796 Rest-frame equivalent width of MgII2796 47- 51 F5.3 0.1nm e_W2796 1σ error on W2796
Note (1): Minimum redshift for a 3σ detection of the MgII2796 line with W>Wmin0.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 2 I2 --- LOS Line of sight number (G1) 4- 20 A17 --- Name Cluster name (1) 22- 26 F5.3 --- z Cluster redshift from RCS (Cat. J/ApJS/157/1) unless flag in r_z col 27 A1 --- r_z [a-f] Reference for z if not RCS (2) 29- 33 F5.3 --- zmin Minimum redshift surveyed 35- 39 F5.3 --- zmax Maximum redshift surveyed 41- 44 F4.2 arcmin dist Projected distance from quasar LOS to cluster coordinates 46- 51 F6.1 kpc dist2 Physical distance at zcluster from quasar LOS to cluster coordinates (in h71-1kpc unit)
Note (1): Names are mostly RCS HHMMSS+DDMM.m (<RCS JHHMMSS+DDMM.m> in Simbad). Note (2): References as follows: a = Faure et al. (2004A&A...428..741F). b = Barkhouse et al. (2006, Cat. J/ApJ/645/955). c = Kneib et al. (2000ApJ...544L..35K). d = Green et al. (2005ApJ...630..142G). e = Stocke et al. (1991, Cat. IX/15). f = Perlman et al. (2002, Cat. J/ApJS/140/265).
Global notes: Note (G1): LOSs 1-19: absorbers found in sample S1 (see table 1); LOSs 20-31: absorbers found in sample S2 (MgII in low-resolution spectra).
History: From electronic version of the journal References: Padilla et al. Paper II. 2009MNRAS.395.1135P
(End) Emmanuelle Perret [CDS] 15-Oct-2010
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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