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 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:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 248 The DLA absorption sample of quasars
table2.dat 38 1959 The pool of control quasars
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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
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Bytes Format Units Label Explanations
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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)
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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
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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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)
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Note (1): Mean signal-to-noise ratio of the SDSS spectrum in the rest-frame
spectral window 1440-1490Å.
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Acknowledgements:
Giovanni Vladilo,
(End) Patricia Vannier [CDS] 07-Jan-2008