J/ApJ/727/47        The MgII cross-section of red galaxies        (Bowen+, 2011)
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The Mg II cross-section of luminous red galaxies.
    Bowen D.V., Chelouche D.
   <Astrophys. J., 727, 47 (2011)>
   =2011ApJ...727...47B
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ADC_Keywords: Galaxies, spectra ; Redshifts ; QSOs ; Equivalent widths
Keywords: galaxies: clusters: general -
          galaxies: elliptical and lenticular, cD - galaxies: groups: general -
          galaxies: halos - quasars: absorption lines

Abstract:
    We describe a search for MgII(2796, 2803) absorption lines in Sloan
    Digital Sky Survey (SDSS) spectra of QSOs whose lines of sight pass
    within impact parameters {rho}~200kpc of galaxies with photometric
    redshifts of z=0.46-0.6 and errors {Delta}z~0.05. The galaxies
    selected have the same colors and luminosities as the Luminous Red
    Galaxy (LRG) population previously selected from the SDSS. A search
    for MgII lines within a redshift interval of +/-0.1 of a galaxy's
    photometric redshift shows that absorption by these galaxies is rare:
    the covering fraction is f({rho})~10%-15% between {rho}=20kpc and
    {rho}=100kpc, for MgII lines with rest equivalent widths of
    W_r_>=0.6{AA}, falling to zero at larger {rho}. There is no evidence
    that W_r_ correlates with impact parameter or galaxy luminosity.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table1.dat    131      593   Mg II absorption in QSO-galaxy pairs
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See also:
  VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
  II/294  : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
  J/ApJS/194/42   : SDSS-DR3 MgII-based black hole masses (Rafiee+, 2011)
  J/ApJ/724/L176  : MgII absorbing gas around galaxies (Chen+, 2010)
  J/ApJ/698/819   : MgII and LRGs cross-correlation analysis (Lundgren+, 2009)
  J/ApJ/679/239   : Associated MgII absorbers (Vanden+, 2008)
  J/ApJ/660/1093  : Weak MgII absorbers at 0.4<z<2.4 (Narayanan+, 2007)
  J/ApJ/639/766   : SDSS-DR3 strong MgII absorbers (Prochter+, 2006)
  J/MNRAS/371/495 : Catalogue of MgII absorbers from SDSS DR3 (Bouche+, 2006)
  J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004)
  J/A+A/410/33    : MgII/FeII absorbers in 2dF-quasar survey (Menard+, 2003)
  J/AJ/106/848    : QSO MgII absorption line systems (Drinkwater+, 1993)
  http://www.sdss.org/ : SDSS home page

Byte-by-byte Description of file: table1.dat
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   Bytes Format Units    Label   Explanations
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   1- 19  A19   ---      QSO     Background SDSS QSO name
                                 (JHHMMSS.ss+DDMMSS.s) (1)
  21- 24  I4    ---      Plate   ? SDSS-DR6 Plate
      25  A1    ---      ---     [-]
  26- 30  I5    ---      MJD     ? SDSS-DR6 Modified Julian Date
      31  A1    ---      ---     [-]
  32- 34  I3    ---      Fib     ? SDSS-DR6 Fiber
  36- 40  F5.3  ---      zQSO    [0.766/2.095]? QSO emission redshift
  42- 60  A19   ---      Gal     Galaxy SDSS name (JHHMMSS.ss+DDMMSS.s)
  62- 66  F5.3  ---      zCC2    [0.459/0.6] Galaxy photometry redshift
  68- 72  F5.3  ---    e_zCC2    Uncertainty in zCC2
  74- 77  F4.1  mag      rmag    Galaxy r band model magnitude de-reddened for
                                 Milky Way dust absorption
  79- 83  F5.1  mag      rMag    SDSS absolute r band magnitude (2)
  85- 88  F4.1  arcsec   ASep    [3.4/30] QSO-galaxy angular separation
  90- 94  F5.1  kpc      rho     [20/197.1] QSO-galaxy impact parameter
  96-101  F6.4  ---      zabs    [0.3779/0.6509]? Mg II absorption redshift (if
                                 doublet detected within {+/-}0.1 of zCC2)
 103-109  F7.4  ---      Dz     ? Difference {Delta}z between zabs and zCC2
     111  A1    ---    l_W2796   The 2{sigma} upper limit flag on W2796
 112-115  F4.2  0.1nm    W2796   Rest MgII (2796) equivalent width
 117-120  F4.2  0.1nm  e_W2796   ? Uncertainty in W2796
     122  A1    ---    l_W2803   The 2{sigma} upper limit flag on W2803
 123-126  F4.2  0.1nm    W2803   Rest MgII (2803) equivalent width
 128-131  F4.2  0.1nm  e_W2803   ? Uncertainty in W2803
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Note (1): Entries are listed in order of increasing QSO-galaxy impact
     parameter. In some cases, multiple galaxies satisfying our selection
     criteria were found around a single sightline. These are also listed,
     but are kept together with a single QSO entry, even though they may
     have much larger impact parameters.
Note (2): Based on zCC2, after applying a K-correction to measure the
     r-band luminosity at a redshift z=0.
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History:
    From electronic version of the journal

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(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    23-Aug-2012