J/A+A/410/33 MgII/FeII absorbers in 2dF-quasar survey (Menard+, 2003)
Investigating lensing by absorbers in the 2dF-quasar survey. Menard B., Peroux C. <Astron. Astrophys. 410, 33 (2003)> =2003A&A...410...33M
ADC_Keywords: QSOs ; Redshifts ; Equivalent widths Keywords: cosmology: observations - quasars: absorption lines - cosmology: gravitational lensing - surveys Abstract: We use the first data release of the 2-degree Field quasar survey (Cat. VII/223) to investigate the effect of gravitational magnification by foreground absorbing systems on background quasars. We select two populations of quasars from this sample: one with strong MgII/FeII absorbers and one without. The selection is done in such a way that the two populations have the same redshift distribution and the absorber detection procedure discards possible biases with quasar magnitude. Description: The first data release of the 2QZ (Cat. VII/223) contains over ten thousand low resolution quasar spectra, taken with the 2-degree Field instrument at the Anglo-Australian Telescope in the range 3700-7500Å. Quasar candidates with 18.25<bJ<20.85 were selected from a single homogeneous color-based catalogue from APM (Automatic Plate Measuring, Cat. I/267) measurements of UK Schmidt photographic material. Note that the corresponding u- and r-band quasar catalogues are therefore not complete. In our study we will use the absorber catalogue compiled by Outram et al. (2001, Cat. J/MNRAS/328/805). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea2.dat 42 110 Detailed list of the quasars with an absorber used in our analysis.
See also: VII/223 : The 2dF QSO Redshift Survey. V. The 10k catalogue (Croom+ 2001) I/267 : The APM-North Catalogue (McMahon+, 2000) J/MNRAS/328/805 : The 2dF QSO Redshift Survey. VIII (Outram+, 2001) Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 16 A16 --- QSO Quasar designation (JHHMMSS.s+DDMMSS) 18- 22 F5.3 --- zem Emission redshift 24- 25 I2 --- S/N Signal-to-noise ratio 27- 31 F5.3 --- zabs Absorption redshift 33- 36 F4.2 0.1nm W0 Rest equivalent width of the MgII doublets 37 A1 --- n_W0 [ab] Note on W0 (1) 39- 42 A4 --- Flag Flags (2)
Note (1): Note on W0 as follows: a = Rest equivalent width of FeII λ=2600Å (MgII blended with sky lines) b = Rest equivalent width of MgII λ=2796Å only Note (2): Flags as follows: A = presence of two absorbers in the quasar spectrum B = presence of two absorbers in the quasar spectrum and one of these two absorbers has z(abs) close to z(QSO) R1 = Quasar not detected in the r-band R2 = Quasar has an absorber escape velocity smaller than 3000km/s.
History: From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 17-Nov-2003
|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|