J/ApJ/613/841 Redshifts in A2125 (Miller+, 2004)
The dynamics of A2125.
Miller N.A., Owen F.N., Hill J.M., Keel W.C., Ledlow M.J., Oegerle W.R.
<Astrophys. J., 613, 841-850 (2004)>
=2004ApJ...613..841M 2004ApJ...613..841M
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: galaxies: clusters: individual (A2125) - galaxies: evolution -
galaxies: kinematics and dynamics
Abstract:
We present 371 galaxy velocities in the field of the very rich cluster
A2125 (z∼0.25). These were determined using optical spectroscopy
collected over several years from both the WIYN 3.5m telescope and
NOAO Mayall 4m telescope. Prior studies at a variety of wavelengths
(radio, optical, and X-ray) have indicated that A2125 is a likely
cluster-cluster merger, a scenario that we are able to test using our
large velocity database. We identified 224 cluster galaxies, which
were subjected to a broad range of statistical tests using both
positional and velocity information to evaluate the cluster dynamics
and substructure. The tests confirmed the presence of substructures
within the A2125 system at high significance, demonstrating that A2125
is a complex dynamical system. Comparison of the test results with
existing simulations strengthens the merger hypothesis and provides
clues about the merger geometry and stage. The merger model for the
system can reconcile A2125's low X-ray temperature and luminosity with
its apparently high richness and might also explain A2125's high
fraction of active galaxies identified in prior radio and optical
studies.
Description:
Observations of A2125 were performed by W. R. Oegerle and J. M. Hill
using the Hydra multifiber spectrograph on the WIYN 3.5m telescope
during a pair of observing runs in 1996. Three fiber configurations
were observed during 1996 April 16-18, and a fourth was observed
during 1996 May 20-22. Additional spectroscopy using Hydra on the WIYN
telescope was performed in the queue observing mode over several
nights from 2000 March through May.
Objects:
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RA (2000) DE Designation(s)
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15 40 58.0 +66 18 30 A2125 = ACO 2125
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 290 Cluster velocity data
table3.dat 104 164 Noncluster redshifts
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See also:
J/AJ/118/625 : Radio sources in Abell 2125 and 2645 (Dwarakanath+, 1999)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 10 F4.1 s RAs Second of Right Ascension (J2000)
12 A1 --- f_RAs [a] Flag on RAs (1)
14 A1 --- DE- Sign of the Declination (J2000)
15- 16 I2 deg DEd Degree of Declination (J2000)
18- 19 I2 arcmin DEm Arcminute of Declination (J2000)
21- 22 I2 arcsec DEs Arcsecond of Declination (J2000)
24- 28 I5 km/s cz Heliocentric velocity (2)
30- 31 I2 km/s e_cz Error in cz
33- 92 A60 --- Lines Emission lines used in determining cz (3)
94- 96 A3 --- Ref Source reference (4)
98 A1 --- f_Ref [b] Flag on Ref (5)
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Note (1): 'a' indicates a binary galaxy, with each nucleus observed
individually in the long slit observations. The 1996 WIYN Hydra
observation is likely a blend of the two nuclei.
Note (2): Heliocentric velocity not relativistically corrected.
Note (3): When the emission lines are enclosed in parentheses,
the velocity was determined through cross correlation but the noted
emission lines were also detected at a consistent velocity.
Note (4): The abbreviations for the data sources are as follows:
W96 = WIYN Hydra 1996;
W00 = WIYN Hydra 2000;
M98 = Mayall 1998.
Note (5): 'b' indicates the peculiar emission line galaxy C153, discussed
in more detail in Dwarakanath & Owen (2001JApA...22....1D 2001JApA...22....1D).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 10 F4.1 s RAs Second of Right Ascension (J2000)
12 A1 --- DE- Sign of the Declination (J2000)
13- 14 I2 deg DEd Degree of Declination (J2000)
16- 17 I2 arcmin DEm Arcminute of Declination (J2000)
19- 20 I2 arcsec DEs Arcsecond of Declination (J2000)
22- 27 F6.4 --- z ? Heliocentric redshift
29 A1 --- f_z [a] Flag on z (1)
31- 36 F6.4 --- e_z ? Error in z
38- 97 A60 --- Lines Emission lines used in determining z (2)
99 A1 --- f_Lines [b] Flag on Lines (3)
101-103 A3 --- Ref Source reference (4)
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Note (1): 'a' indicates a probable quasar; velocity and error not listed
as unique identification of emission features was not determined.
Note (2): When the emission lines are enclosed in parentheses, the
redshift was determined through cross correlation but the noted
emission lines were also detected at a consistent redshift.
Note (3): 'b' indicates a strong narrow emission line galaxy.
Other detected lines include [NeIII]λ(3869),
[HeI]+Hλ(3889), [NeIII] + Hλ(3967),
Hδλ(4102), and [OIII]λ(4363).
Note (4): The abbreviations for the data sources are as follows:
W96 = WIYN Hydra 1996;
W00 = WIYN Hydra 2000;
M98 = Mayall 1998.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 16-Mar-2005