J/ApJ/692/511        Mergers of luminous early-type galaxies        (Wen+, 2009)
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Mergers of luminous early-type galaxies in the local universe and gravitational
wave background.
    Wen Z.L., Liu F.S., Han J.L.
   <Astrophys. J., 692, 511-521 (2009)>
   =2009ApJ...692..511W
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ADC_Keywords: Photometry, SDSS ; Galaxies, optical ; Redshifts
Keywords: black hole physics - galaxies: general - galaxies: interactions -
          gravitational waves

Abstract:
    Supermassive black hole (SMBH) coalescence in galaxy mergers is
    believed to be one of the primary sources of very low frequency
    gravitational waves (GWs). Significant contribution of the GWs comes
    from mergers of massive galaxies with redshifts z<2. Very few
    previous studies gave the merger rate of massive galaxies. We selected
    a large sample (1209) of close pairs of galaxies with projected
    separations 7<r_p_<50kpc from 87889 luminous early-type galaxies
    (M_r_<-21.5) from the Sloan Digital Sky Survey Data Release 6. These
    pairs constitute a complete volume-limited sample in the local
    universe (z<0.12). Using our newly developed technique, 249 mergers
    have been identified by searching for interaction features. From them,
    we found that the merger fraction of luminous early-type galaxies is
    0.8%, and the merger rate in the local universe is
    Rg~(1.0+/-0.4)x10^-5^Mpc^-3^/Gyr with an uncertainty mainly depending
    on the merging timescale.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table1.dat    110     1209   A list of luminous early-type galaxy pairs from
                             SDSS DR6
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See also:
   II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
   J/ApJ/685/235 : Host and companion galaxies in the SDSS (Patton+, 2008)
   J/AJ/132/2596 : Spectroscopy of Ultraluminous IR galaxies (Darling+, 2006)
   J/AJ/126/1183 : Major galaxy mergers at z<~3 (Conselice+, 2003)
   J/ApJ/565/208 : Galaxy pairs in the CNOC2 Redshift Survey (Patton+, 2002)
   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-  4  I4    ---     Seq       [1/1209] Pair identification number
                                  <[WLH2009] NNNN> in Simbad
   6- 14  F9.5  deg     RA1deg    First galaxy Right Ascension (J2000)
  16- 24  F9.5  deg     DE1deg    First galaxy Declination (J2000)
  26- 34  F9.5  deg     RA2deg    Second galaxy Right Ascension (J2000)
  36- 44  F9.5  deg     DE2deg    Second galaxy Declination (J2000)
  46- 50  F5.2  mag     r1mag     First galaxy SDSS r-band magnitude
  52- 56  F5.2  mag     r2mag     Second galaxy SDSS r-band magnitude
  58- 63  F6.2  mag     r1MAG     Frist galaxy fitted absolute r-band magnitude
  65- 70  F6.2  mag     r2MAG     Second galaxy fitted absolute r-band magnitude
  72- 76  F5.2  kpc     Sep       Pair separation
  78- 82  F5.2  ---     a         Pair asymmetry factor
  84- 88  F5.2  mag     rres      Pair residual r-band magnitude
  90- 95  F6.4  ---     z         Pair redshift
  97- 98  A2    ---   f_z         sp for spectroscopic or ph for photometric
                                  redshift
 100-110  A11   ---     Class     Merging/non-merging system classification
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Nomenclature notes:
    Galaxies are <[WLH2009] JDDD.ddddd+DD.ddddd> in Simbad.

History:
    From electronic version of the journal

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(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    03-Mar-2011