J/AJ/118/625 Radio sources in Abell 2125 and 2645 (Dwarakanath+, 1999)
On the different radio source populations in the Butcher-Oemler clusters
Abell 2125 and 2645.
Dwarakanath K.S., Owen F.N.
<Astron. J. 118, 625 (1999)>
=1999AJ....118..625D 1999AJ....118..625D (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Radio sources
Keywords: galaxies: clusters: individual (Abell 2125, Abell 2645) -
galaxies: starburst - radio continuum
Abstract:
The Abell clusters 2125 and 2645 have different radio source
populations, despite being very similar in richness (Abell class 4)
and redshift (0.25). The number density of radio sources in Abell 2125
is almost an order of magnitude more than that in Abell 2645, based on
observations to the same optical and radio luminosities of the two
clusters. About 30% of the radio sources in Abell 2125 shows signs of
star formation, with the largest concentration of them in the
southwest clump 2Mpc from the cluster center.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 61 54 Abell 2125: optical identifications
table3.dat 61 36 Abell 2645: optical identifications
--------------------------------------------------------------------------------
Table 1: Relevant cluster and observational parameters
--------------------------------------------------------------------------------
Cluster z N30 fB Field center VLA Beam PA rms
RA (2000) DE " deg uJy/beam
--------------------------------------------------------------------------------
Abell 2125 0.2460 62 0.19 15 41.0 +66 18.5 C 13.7 x 11.5 -7.4 25
15 41.2 +66 16. A 1.83 x 1.73 -48.4 ∼30
Abell 2645 0.2500 35 0.03 23 41.6 -09 01.4 B 5.33 x 4.15 +2.2 27
Abell 370 0.373 107 0.21 02 36.5 -01 34.9 B 5.22 x 4.25 +23.1 12
Cl 0024+1654 0.391 87 0.16 00 26.6 +17 10.6 B 4.53 x 4.32 +23.8 10
--------------------------------------------------------------------------------
Notes: N30 is a measure of cluster richness. It indicates 30% of the total
number of cluster members brighter than MV=-20.
fB, the fraction of blue galaxies in a cluster, s the fraction of the
total net cluster population with rest-frame B-V colors at least
0.2mag bluer than those of the early-type galaxies (Butcher & Oemler,
1984ApJ...285..426B 1984ApJ...285..426B).
VLA configurations A, B, and C have maximum baselines of approximately
35, 11, and 3 km, respectively.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- [DO99] Sequential number (1)
4- 5 I2 h RAh Radio right ascension (J2000.0)
7- 8 I2 min RAm Radio right ascension (J2000.0)
10- 14 F5.2 s RAs Radio right ascension (J2000.0)
16 A1 --- DE- Radio declination sign (J2000.0)
17- 18 I2 deg DEd Radio declination (J2000.0)
20- 21 I2 arcmin DEm Radio declination (J2000.0)
23- 26 F4.1 arcsec DEs Radio declination (J2000.0)
28- 31 F4.2 arcsec Sep Radial distance between the optical and
radio positions
33- 36 F4.1 arcsec Ext1 ? Extent (as measured in the radio image)
38- 41 F4.1 arcsec Ext2 ? Extent (as measured in the radio image)
43- 45 I3 deg PA ? Position angle
47 A1 --- Memb [Y/N] Member?
49 A1 --- StarFor [Y/N] Star formation?
51- 55 I5 uJy S20cm Flux density at 20cm
57- 61 F5.1 10+22W/Hz L20cm ? Luminosity at 20cm (2)
--------------------------------------------------------------------------------
Note (1): Designation in Simbad:
Table2: [DO99] ACO 2125 NN in Simbad
Table3: [DO99] ACO 2645 NN in Simbad
Note (2): The luminosities are in the observer's rest frame and are estimated
using z=0.2460, H0=75km/s/Mpc, and q_0-=0.1.
--------------------------------------------------------------------------------
History: From AJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 21-Oct-1999