Access to Astronomical Catalogues

← Click to display the menu
J/A+A/478/701   Color excess of SDSS quasars with DLA systems  (Vladilo+, 2008)

The color excess of quasars with intervening DLA systems. Analysis of the SDSS data release five. Vladilo G., Prochaska J., Wolfe A.M. <Astron. Astrophys. 478, 701 (2008)> =2008A&A...478..701V
ADC_Keywords: QSOs ; Redshifts ; Photometry Keywords: ISM: dust, extinction - galaxies: ISM - galaxies: high-redshift - quasars: absorption lines Abstract: We analyzed the spectroscopic and photometric database of the 5th data release of the Sloan Digital Sky Survey (SDSS) to search for evidence of the quasar reddening produced by dust embedded in intervening damped Lyα (DLA) systems. From a list of 5164 quasars in the interval of emission redshift 2.25≤ze≤3.5 and SDSS spectra with signal-to-noise ratio SNR≳4, we built up an "absorption sample" of 248 QSOs with a single DLA system in the interval of absorption redshift 2.2<za≤3.5 and a "pool" of 1959 control QSOs without DLA systems or strong metal systems. For each QSO of the absorption sample we extracted from the pool a subset of control QSOs that are closest in redshift and magnitude. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 104 248 The DLA absorption sample of quasars table2.dat 38 1959 The pool of control quasars
See also: http://www.sdss.org/ : The SDSS Home Page J/MNRAS/354/L31 : SDSS DR2 QSO and DLA properties (Murphy+, 2004) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 19 A19 --- SDSS SDSS identifier of the DLA quasar (JHHMMSS.ss+DDMMSS.s) 21- 24 F4.2 --- zem Emission redshift of the quasar 26- 30 F5.2 mag rmag SDSS r magnitude 32- 36 F5.3 --- zabs Absorption redshift 38- 42 F5.2 cm-2 logN(HI) HI column density of the DLA system 44- 47 F4.2 --- d(zem) bin in zem of the subset of control quasars (1) 49- 52 F4.2 mag d(rmag) bin in rmag of the subset of control quasars (2) 54- 59 F6.3 mag <(r-z)0> Mean (r-z) color of the control sub-set (3) 61- 65 F5.3 mag e_<(r-z)0> Standard deviation of the mean <(r-z)_0> 67- 72 F6.3 mag <(g-z)0> Mean (g-z) color of the control sub-set (3) 74- 78 F5.3 mag e_<(g-z)0> Standard deviation of the mean <(g-z)_0> 80- 85 F6.3 mag D(r-z) Deviation from mean (r-z) color index (4) 87- 91 F5.3 mag e_D(r-z) Error of Delta(r-z) 93- 98 F6.3 mag D(g-z) ?=- Deviation from mean (g-z) color index (4) 100-104 F5.3 mag e_D(g-z) ? Error of Delta(g-z)
Note (1): Width of the bin in emission redshift adopted for selecting the sub-set of control quasars Note (2): Width of the bin in r magnitude adopted for selecting the sub-set of control quasars Note (3): Mean color and dispersion of the sub-set of control quasars selected at the same zem and rmag of the DLA-quasar Note (4): Deviation from the mean color of the DLA-quasar
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 18 A18 --- SDSS SDSS identifier of the control quasar (HHMMSS.ss+DDMMSS.s, J2000) 21- 24 F4.2 --- zem emission redshift of the control quasar 27- 31 F5.2 mag rmag SDSS r magnitude of the control quasar 37- 38 I2 --- S/N Mean signal-to-noise ratio of the SDSS spectrum (1)
Note (1): Mean signal-to-noise ratio of the SDSS spectrum in the rest-frame spectral window 1440-1490Å.
Acknowledgements: Giovanni Vladilo,
(End) Patricia Vannier [CDS] 07-Jan-2008
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

catalogue service

© UDS/CNRS

Contact