J/ApJ/692/511 Mergers of luminous early-type galaxies (Wen+, 2009)
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 2009ApJ...692..511W
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<rp<50kpc from 87889 luminous early-type galaxies
(Mr←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)x10-5Mpc-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
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 03-Mar-2011