J/AJ/129/31 A deep radio survey of Abell 2125. II (Owen+, 2005)
A deep radio survey of Abell 2125.
II. Accelerated galaxy evolution during a cluster-cluster merger.
Owen F.N., Ledlow M.J., Keel W.C., Wang Q.D., Morrison G.E.
<Astron. J., 129, 31-52 (2005)>
=2005AJ....129...31O 2005AJ....129...31O
ADC_Keywords: Clusters, galaxy ; Photometry ; Radio sources
Keywords: cosmology: observations -
galaxies: clusters: individual (Abell 2125) -
galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: starburst - infrared: galaxies
Abstract:
Using our extensive radio, optical, near-IR, and X-ray imaging and
spectroscopy, we consider the reason for the unusually large number of
radio-detected galaxies, mostly found outside the cluster core, in
Abell 2125 (z=0.2465, richness class 4). With 20cm VLA data, we detect
continuum emission from 90 cluster members. The multiwavelength
properties of these galaxies suggest that most of the radio emission
is due to an enhanced star formation rate. The recent dynamical study
of Miller et al. (2004, Cat. J/ApJ/613/841) suggests that A2125 is
undergoing a major cluster-cluster merger, with our view within
30° of the merger axis and within 0.2Gyr of core passage. The
combination of projection effects and the physical processes at work
during this special time in the cluster's evolution seem likely to be
responsible for the unusual level of activity we see in the cluster.
We argue that tidal effects on individual cluster members, often far
from the cluster core, are responsible for the increased star
formation. Our results are consistent with the idea that disk galaxies
during this phase of a cluster's evolution undergo rapid evolution
through a burst of star formation on their way to becoming S0
galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 90 A2125 member radio sources
table2.dat 66 90 A2125 Gunn-Oke magnitudes
table4.dat 49 90 A2125 member physical parameters
table8.dat 34 90 A2125 star-formation index
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See also:
J/AJ/129/26 : A deep radio survey of Abell 2125. I (Owen+, 2005)
J/ApJ/613/841 : Redshifts in A2125 (Miller+, 2004)
J/AJ/118/625 : Radio sources in Abell 2125 and 2645 (Dwarakanath+, 1999)
J/ApJ/611/821 : X-raying A2125 (Wang+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Source name (G1) (1)
7- 8 I2 h RAh Hour of Right Ascension (J2000)
10- 11 I2 min RAm Minute of Right Ascension (J2000)
13- 17 F5.2 s RAs Second of Right Ascension (J2000)
19- 22 F4.2 s e_RAs Estimated error in RAs
24- 25 I2 deg DEd Degree of Declination (J2000)
27- 28 I2 arcmin DEm Arcminute of Declination (J2000)
30- 33 F4.1 arcsec DEs Arcsecond of Declination (J2000)
35- 37 F3.1 arcsec e_DEs Estimated error in DEs
39- 42 F4.1 Mpc Dist Distance from the nominal cluster center (2)
44- 50 F7.1 uJy Sp20cm Uncorrected peak flux density in
units of µJy/beam size
52- 58 F7.1 uJy S20cm Corrected total flux density
60- 64 F5.0 uJy e_S20cm Estimated error in S20cm
66 A1 --- l_Size [<] Limit flag on Size
67- 70 F4.1 arcsec Size Best fit size, major axis (3)
71 A1 --- --- [x]
72- 74 F3.1 arcsec Size1 ? Best fit size, minor axis (3)
76- 78 I3 arcsec PA ? Best fit size, position angle (3)
80- 85 F6.4 --- z Redshift
86 A1 --- n_z [e] Indicates emission lines were present
in the spectrum (Miller et al. 2004, Cat.
J/ApJ/613/841)
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Note (1): For members identified with radio emission detected at >5σ
above the noise.
Note (2): Where the center is RA=15:41:15.00 and DE=66:16:00.0.
Note (3): If the source is resolved and fitted with a two dimensional Gaussian,
we give the deconvolved major axis size (FWHM), the minor axis size
and the position angle. If only a size is given, this value has been
estimated from the image by hand.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Source name (G1)
7- 11 F5.2 mag Umag Gunn-Oke aperture U band AB magnitude
13- 17 F5.2 mag Bmag Gunn-Oke aperture B band AB magnitude
19- 23 F5.2 mag Vmag Gunn-Oke aperture V band AB magnitude
25- 29 F5.2 mag Rmag Gunn-Oke aperture R band AB magnitude
31- 35 F5.2 mag Imag Gunn-Oke aperture I band AB magnitude
37- 41 F5.2 mag 8010mag Gunn-Oke aperture 8010Å band AB magnitude
43- 47 F5.2 mag 9170mag Gunn-Oke aperture 9170Å band AB magnitude
49- 53 F5.2 mag Jmag ?=-9.00 Gunn-Oke aperture J band AB magnitude
55- 59 F5.2 mag Hmag ?=-9.00 Gunn-Oke aperture H band AB magnitude
61- 65 F5.2 mag Kmag ?=-9.00 Gunn-Oke aperture K band AB magnitude
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Source name (G1)
7 A1 --- l_size Limit flag on size
8- 12 F5.1 kpc size Largest linear size
14- 18 F5.2 [W/Hz] logL20 Log of the absolute 20cm luminosity
20- 23 F4.2 Mpc pDist Projected distance from cluster center
25- 29 F5.1 mag RMAG Absolute rest frame R band magnitude
31 I1 --- sp The hyperz spectral type (1)
33- 36 F4.1 Gyr Age The hyperz age (1)
38- 40 F3.1 mag AV The hyperz V band extinction (1)
42- 47 F6.4 --- z Redshift
48 A1 --- n_z [e] Indicates emission lines were present in
the spectrum (Miller et al. 2004,
Cat. J/ApJ/613/841)
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Note (1): Hyperz is a public photometric redshift code
(Bolzonella, Miralles & Pello, 2000A&A...363..476B 2000A&A...363..476B).
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Source name (G1)
7- 9 F3.1 --- L20cm 20cm luminosity property "star-formation index"
score
11- 13 F3.1 --- sAlign Align property "star-formation index" score
15- 17 F3.1 --- sMag Magnitude property "star-formation index" score
19- 21 F3.1 --- sEmis Emission property "star-formation index" score
23- 25 F3.1 --- sAge Age property "star-formation index" score
27- 29 F3.1 --- sDust Dust property "star-formation index" score
31- 33 F3.1 --- sTotal Total "star-formation index" score
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Global Notes:
Note (G1): The first two digits are the facet number and the
last three a sequence number.
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History:
* 06-Jul-2005: From electronic version of the journal
* 10-Jul-2007: inconsistencies between tables 2 and 4:
-- table2, record#18: name changed from 18071 to 18701
-- table4, record#19: z changed to 0.2558 (Miller 2004ApJ...613..841M 2004ApJ...613..841M)
-- table4, record#37: z changed to 0.2430 (Miller 2004ApJ...613..841M 2004ApJ...613..841M)
-- table4, record#53: z changed to 0.2560 (Miller 2004ApJ...613..841M 2004ApJ...613..841M)
References:
Owen et al., Paper I 2005AJ....129...26O 2005AJ....129...26O, Cat. J/AJ/129/26
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 06-Jul-2005