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J/MNRAS/354/L31     SDSS DR2 QSO and DLA properties       (Murphy+, 2004)
Dust-reddening and gravitational lensing of SDSS QSOs due to foreground
damped Lyman α systems.
    Murphy M.T., Liske J.
   <Mon. Not. R. Astron. Soc., 354, L31-L36 (2004)>
   =2004MNRAS.354L..31M
ADC_Keywords: QSOs ; Redshifts ; Equivalent widths

Keywords: dust, extinction - galaxies: high-redshift - intergalactic medium -
          galaxies: ISM - quasars: absorption line

Abstract:
    We use Sloan Digital Sky Survey (SDSS) Data Release 2 quasi-stellar
    object (QSO) spectra to constrain the dust-reddening caused by
    intervening damped Lyman α systems (DLAs). Comparing the
    spectral index distribution of a 70 sight-line DLA sample with that of
    a large control sample reveals no evidence for dust-reddening at z∼3.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        97     1979   Catalogue of DR2 QSO and DLA properties.


See also:
 J/AJ/126/2579   : SDSS quasar catalog. First data release (Schneider+, 2003)
 J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004)
 http://www.sdss.org/dr2 : SDSS-DR2 Home Page


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1- 18  A18   ---     SDSS      SDSS J2000 name of the QSO derived from the RA
                                   and DEC supplied in the FITS headers of the
                                   spectra (HHMMSS.ss+DDMMSS.s)
  20- 25  F6.4  ---     z         SDSS emission redshift of the QSO given in the
                                   FITS headers of the spectra.
  27- 32  F6.3  mag     r'mag     r'-band PSF magnitude corrected for
                                   Galactic extinction
  34- 39  F6.3  mag     i'mag     i'-band PSF magnitude corrected for
                                   Galactic extinction
  41- 46  F6.3  mag     z'mag     z'-band PSF magnitude corrected for
                                   Galactic extinction
  48- 53  F6.3  ---     Sp+Index  Spectral index.
  55- 59  F5.3  ---   e_Sp+Index  1-sigma statistical error in spectral index
  61- 65  F5.2  ---     S/Nmin    Minimum signal-to-noise ratio
  67- 72  F6.4  ----    zabs      ?=0.0000 Absorption redshift of the DLA
                                    (approximate only)
  74- 79  F6.3  0.1nm   EWHa      ?=0.000 Rest-frame equivalent width of the
                                     damped Lyman alpha line
  82- 86  F5.3  0.1nm   e_EWHa    ?=0.000 1-sigma statistical error in EWHa
      88  I1    ---     DLA       [0/2] Status of DLA detection (1)
      91  I1    ---     Target    [0/1] Primary (1) or secondary (0) SDSS target
      94  I1    ---     DR1       [0/1] QSO appears (1) or did not appears (0)
                                        in SDSS DR1 QSO catalogue
                                        (Cat. J/AJ/126/2579)
      97  I1    ---     BAL       [0/1] QSO deemed (1) or not deemed (0)
                                        to have BALs (2)

Note (1): Damped Lymanα (DLA) detection flags as follows:
      0 = indicates no DLA detected
      1 = indicates that the DLA detection is plausible, though
          unconvincing and so is excluded from further analysis (i.e. this
          sight-line appears in neither the DLA or control samples)
      2 = indicates that the DLA detection is taken to be genuine
Note (2): Flag indicating whether the QSO was judged, by visual inspection, to
          have some moderately strong Broad Absorption Lines (BALs) in its
          spectrum.


History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    29-Apr-2005