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1996AuJPh..49..977Slee,Roy & Andernach
A VLA Survey of Rich Clusters of Galaxies III. The weaker sources
Abstract
We present radio and optical parameters for 737 weak sources in 60 Abell
cluster fields observed with the Very Large Array (VLA) using scaled
arrays at 1.5 and 4.9 GHz. The measurements extend to a lower 1.5 GHz limit
of 1.0 mJy and comprise a complete sample with 1.5-GHz flux density 2.5
S1.5 < 20 mJy The combined sky area within the half-power circle on the
maps is 3.5 x 10-3 sr, and the cluster fields are distributed over 24 h of
right ascension and between declinations +35deg and -30deg. Contour maps
of the extended sources at 1.5 GHz are presented and source parameters
such as position, angular size and spectral index are tabulated. We also
derive the emitted power and linear size for those sources with published
redshifts. We try to identify the radio sources with optical images on the
Palomar and SERC survey plates and give their accurate optical positions,
morphologies and apparent magnitudes.
J/AuJPh/47/145 VLA Survey of Rich Clusters of Galaxies II (Slee+, 1994)
J/AuJPh/49/977 VLA Survey of Rich Clusters of Galaxies III (Slee+, 1996)
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A VLA Survey of Rich Clusters of Galaxies II. The Stronger Sources: Maps,
Polarisations and Identifications
Slee O.B., Roy A., Savage A.
A VLA Survey of Rich Clusters of Galaxies III. The Weaker Sources: Maps
and Identifications
Slee O.B., Roy A., Andernach H.
=1994AuJPh..47..145S (SIMBAD/NED BibCode)
=1996AuJPh..49..977S (SIMBAD/NED BibCode)
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Keywords: galaxies: clusters of - radio continuum: galaxies; surveys -
radio sources: optical identification
Description:
We observed 60 fields towards 57 Abell and one Zwicky cluster of galaxies
using the Very Large Array (VLA) with scaled arrays at 1.5 and 4.9 GHz.
The source catalogue contains radio and optical parameters for 994 sources
up to a lower flux limit of 1.0 mJy at 1.5 GHz and comprises a complete sample
above 2.5 mJy. The combined sky area within the half-power circle on the maps
is 3.5 10^-3 sr, and the cluster fields are distributed between +35 deg
and -30 deg declination. The source catalogue list positions, angular
size, spectral index and optical identification, magnitude and morphology,
if available.
See also:
1989AuJPh..42..633Slee+; Catalogue of 937 Radio Sources towards
58 Galaxy Clusters (= paper I)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 105 60 Properties of the observed clusters
catalog 109 1037 Radio and optical parameters of sources
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Note on catalog:
The source catalogues from papers II and III were merged, as well as
the radio and the optical information joined into a single table. For
each source only the most likely optical candidates (if any) were
retained. This merged table replaces the one published in paper I
=1989AuJPh..42..633Slee+ ). Tables on structural details of multiple
sources as published in papers II and III are available upon request
to the authors.
Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 7 A7 --- Field Name of observed field (1)
9 A1 --- fnote Note on the field (2)
11- 12 I2 h RAh Right ascension of cluster centre(1950) (3)
14- 17 F4.1 min RAm Right ascension of cluster centre(1950) (3)
19 A1 --- DE- Declination sign
20- 21 I2 deg DEd Declination of cluster centre (1950) (3)
23- 24 I2 arcmin DEm Declination of cluster centre (1950) (3)
27- 30 F4.1 arcmin ROoff Offset of radio field centre from optical
cluster centre
33- 36 F4.2 --- offRcl Offset of radio field centre from optical
cluster centre in units of cluster radii
38- 43 F4.1 deg ROPang Position angle of vector from optical
cluster centre to radio field centre
(positive from N through E)
46- 48 I3 uJy/beam rms_1.5 rms noise of radio map at 1.5 GHz
50- 52 I3 uJy/beam rms_4.9 rms noise of radio map at 4.9 GHz
55 I1 --- Rclass Abell richness class of cluster
57 I1 --- Dclass Abell distance class of cluster
59- 62 F4.1 mag m10R red magnitude of 10th brightest galaxy
64- 69 A6 --- BMclass Bautz-Morgan (BM) class of cluster
70 A1 --- u_BM [ :] uncertainty flag on BM class
72- 73 A2 arcmin R_clu angular cluster radius (4)
76- 79 F4.2 Mpc Rclin linear cluster radius (H0=75km/s/Mpc)
82- 87 F6.4 --- zclu cluster redshift
90 A1 --- zref reference for cluster redshift (5)
93- 97 F5.2 erg/s lgxein log of EINSTEIN X-ray luminosity (6)
99 A1 --- lxflag [ R] R= ROSAT measurement converted to
EINSTEIN luminosity scale (see paper)
101- 105 F5.2 erg/s lgxros log of ROSAT X-ray luminosity from
Ebeling 1993 (PhD MPE Garching)
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Note (1):
'A' stands for 'Abell cluster' and Z1518.8 stands for the Zwicky cluster
Zw1518.8+0747. Two clusters (A 85 and A154) were observed with two
different field centers.
Note (2):
*= The RA is from Abell et al. (1989). The incorrect RA of Abell (1958)
was used for the radio field centre - hence the large offset.
#= Data from Abell et al. (1989) =1989ApJS...70....1A
×= Data from "Catalogue of Galaxies and of Clusters of Galaxies"
(Zwicky et al. 1961) and Slee & Quinn (1979) =1979PASAu...3..332S
Note (3):
The centroid position (B1950) of the optical cluster, mainly from
Abell (1958) (=1958ApJS....3..211A), but data for three clusters come
from Abell et al. (1989) (=1989ApJS...70....1A) and Zwicky et al. (1961).
Note (4):
Rclu is the cluster radius from the Palomar Sky Survey
(Struble & Rood 1987 =1987ApJS...63..555S) except that the Abell
radius (approximately 1.72/z arcmin) is quoted for A3528, Zw1518.8, A4038.
Note (5):
Redshift references :
1 Struble & Rood =1991ApJS...77..363S
2 From the m10-z relation =1994AuJPh..47..145S
(Slee, Roy & Savage SRS94, Paper II)
3 Melnick & Quintana =1981A&AS...44...87M
4 Abell et al. =1989ApJS...70....1A
5 Beers et al. =1991AJ....102.1581B
6 Slee & Reynolds =1984PASAu...5..516S
7 Reynolds 1986 =1986USydn.T00J....R
8 Postman et al. =1992ApJ...384..404P
Note (6):
The EINSTEIN X-ray luminosity in the energy range 0.5-4.5 keV and out to a
radius of 1Mpc from the cluster centre. The data (scaled to H_o=75 km/s/Mpc)
are from Jones & Forman (1995, unpubl.).
Byte-by-byte Description of file: tab25
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Name of cluster (A=Abell, Z=Zwicky) (1)
16 A1 --- multID [ #] # denotes one of several optical
identifications for the same source
17 A1 --- IDnum Sequence number of optical ID
20- 21 I2 h RAh Right ascension of radio centroid (1950)
22- 23 I2 min RAm Right ascension of radio centroid (1950)
24- 28 F5.2 s RAs Right ascension of radio centroid (1950)
30 A1 --- DE- Declination sign
31- 32 I2 deg DEd Declination of radio centroid (1950)
33- 34 I2 arcmin DEm Declination of radio centroid (1950)
35- 38 F4.1 arcsec DEs Declination of radio centroid (1950)
40- 41 A2 --- paper number of paper in which the source was
published ('2 '=II; ' 3'=III; '23'=both)
43- 46 F4.2 --- pdist projected distance of radio source from
cluster center in units of Rc (see table1)
48- 53 F6.1 mJy F1.5 integrated 1.5GHz flux density
55- 59 F5.1 mJy F4.9 integrated 4.9GHz flux density
61- 64 F4.1 --- alpha spectral index between 1.5 and 4.9 GHz (2)
67- 69 I3 arcsec majax size of source major axis (deconvolved) (3)
71- 72 I2 arcsec minax size of source minor axis (deconvolved) (3)
74- 76 I3 deg PosAng position angle of major axis (N thru E)
78- 81 A4 --- omorph optical morphology of most likely ID (4)
82 A1 --- Rmag_flg [ >] upper limit flag for Rmag (4)
83- 86 F4.1 mag Rmag red magnitude from POSS prints (4)
88- 91 F4.1 mag Jmag blue (B_j) magnitude from SERC plates (4)
94- 95 I2 arcsec ORoff Positional offset of opt. ID with respect to
radio centroid
97-100 I4 deg offPA Position angle of vector pointing from radio
centroid to opt. ID (positive N through E)
103-108 F6.4 --- z heliocentric redshift of opt. ID, if
available (references see paper)
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Note (1):
The source name is composed of the name of cluster (A=Abell, Z=Zwicky, in
A5 format), an underscore symbol, the source running number within the
observed field (optionally appended by a roman numeral), and an optional list
of subcomponents (a, ab, abc...) which indicate the presence of more detailed
structural data in tables 3 and 4 of both papers II and III. Note that Z1518
stands for the Zwicky cluster Zw1518.8+0747. The source running numbers are
those of paper I. However, a few of the weak sources listed in Paper I (e.g.
A0133_10) were omitted because subsequent analysis showed that they were
probably spurious. To avoid later confusion, the additional sources are
inserted in the Table at the correct right ascension but are given an
extra lower case Roman numeral. For example, the source A0013_13 in table 2
of paper I is now A0013_13i, while the source A0013_13ii_ab of slightly
later RA (as well as two components a and b) has been inserted in the
present source list. In one case two sources (A1913_6 and A1913_8) were
merged to a single source (A1913_6,8).
Note (2):
The spectrum is defined as F(freq)~freq^alpha. The spectral index is
between 1.5 and 4.9 GHz. When no 4.9 GHz flux is listed in the table,
the spectral index is between 1.5 GHz and another frequency taken from
references quoted in the printed version of the papers.
Note (3):
An elliptical Gaussian was fitted to the source. The quoted values are
the full widths at half power, deconvolved with the antenna beam,
and corrected for bandwidth smearing.
Note (4):
The optical identifications were classified into the following categories:
E = elliptical galaxy (ie. visibly extended, surrounded by a diffuse
structureless halo with axial ratio <~2
D = elliptical galaxy several times larger than all neighbouring galaxies
if well away from cluster centre
cD = same as D if close to the cluster centre
DB = two barely resolved elliptical galaxies (dumb-bell galaxy)
G = galaxy (diffuse image too faint to assign a galaxy class)
Q = quasar known from literature
S0 = as 'E' above but with an axial ratio >~2
Sp = spiral galaxy (galaxy with considerable structure in the halo)
St = image with a sharp circular boundary and sometimes showing
diffraction spikes
The symbol 'x2' is appended to double objects, for which the summed magnitude
is quoted in the subsequent colums. Very faint images are difficult
to assign to the G or St categories and often the choice is rather arbitrary.
If an image was detected on the B_j plates, but not on the red POSS prints
a conservative upper limit of ">19.5" is quoted for the red magnitude.
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(End) Heinz Andernach [IUE Vilspa] 23-Oct-1996