J/A+AS/74/315 327 MHz Survey of the A262 cluster region (Righetti+, 1988)
Survey at 327 MHz of the A 262 cluster region.
Righetti G., Giovannini G., Feretti L.
<Astron. Astrophys. Suppl. Ser. 74, 315 (1988)>
=1988A&AS...74..315R 1988A&AS...74..315R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, radio
Keywords: radio sources: general - radio continnum - surveys
Description:
This catalog contains a survey at 327 MHz of the A262 cluster region.
The survey was performed with the WSRT Telescope in the redundancy
mode, and covers a circular region of 21 square degrees towards A262
(RA = 01h49m50s, decl = 35d54'20" -- B1950). The synthesized beam
width is 56" x 93" (RA x DEC). 309 sources were detected, with a
detection limit of 7 mJy (∼5 sigma) at the field center. Nine of these
galaxies have been identified with galaxies of the A262 cluster.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
rad_a262.dat 89 309 327 MHz Survey of Abell 262
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See also:
Byte-by-byte Description of file: rad_a262.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Name of source (1)
8- 9 I2 h RAh Right Ascension (B1950) (hour) (2)
10-11 I2 min RAm Right Ascension (B1950) (min)
12-15 F4.1 s RAs Right Ascension (B1950) (sec)
16 A1 --- DE- Declination sign (B1950) (2)
17-18 I2 deg DEd Declination (B1950) (deg)
19-20 I2 arcmin DEm Declination (B1950) (arcmin)
21-22 I2 arcsec DEs Declination (B1950) (arcsec)
25-28 F4.2 deg r Distance from pointing center (3)
31-34 I4 mJy Smap Flux density measured on map (4)
37-40 I4 mJy Ssky Flux density corrected for attenuation (4)
44-46 I3 arcsec tt ? Angular (DECONVOLVED or SKY) extent (5)
50-52 I3 deg pa ? Position angle N to E of major axis (5)
54-56 A3 --- ID Optical identification (6)
59-62 F4.1 arcsec oRA ? RA difference radio minus optical position (7)
64-68 F5.1 arcsec oDE ? Dec Difference radio minus optical position (7)
70-89 A20 --- Notes Notes (8)
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Note (1): This column contains the name of the source, consisting of the
Westerbork survey number (73W) followed by a sequence number in
order of right ascension. Source '73W076' is a double and both
components are listed separately; '73W076a' and '73W076b'.
Note (2): These columns contain the B1950 source position. The positional
accuracy depends on the source strength and size; it is estimated
to be ∼4" in right ascension and ∼7" in declination for the
weakest point sources, and becomes 2.4" and 4" respectively, for
the sources with flux density > 14 mJy.
Note (3): This column contains the distance from the pointing center, in
degrees. This value is used to obtain the correction for primary
beam attenuation.
Note (4): The Smap column contains the source flux density, as measured on
the map (in mJy). The Ssky column contains the source flux
density corrected for the primary beam attenuation. The
attenuation factor is calculated as f(r) = cos-6 * (21.154 * r)
(ref. Oort, 1987), where 'r' is the distance from the pointing
center, given above.
Note (5): These columns give the angular extent, in arcsec (deconvolved),
and the position angle, N to E, in degrees of the major axis of
the radio brightness.
Note (6): This column gives the optical identification of the source as
follows:
BO: Blue stellar object
QSO: Quasar
R: Red stellar object
GAL: Galaxy
EF: Empty field
There are 227 empty fields, corresponding to 74% of the sample.
The identification rate is independent of the flux density.
Identifications are accepted when the positions agree to within 3
sigma (see text (1988A&AS...74..315R 1988A&AS...74..315R) for definition of sigma).
Note (7): These columns give the 'radio minus optical' positional
difference between the radio and optical positions (RA and Dec,
respectively), in arcsec.
Note (8): This column marks notes on the optical identification. Due to the
large uncertainty on the radio positions, a high contamination
from chance coincidences is expected. For this reason,
identifications with coincidence less than 2 sigma are
differentiated from those between 2 and 3 sigma. The latter,
which should be considered less reliable, are marked with an
asterisk in this column. Where available, the name of the cluster
galaxies is also given.
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References:
Oort, M. J. A. 1987, Phd Thesis, Leiden.
History:
"The catalogue was originally archived as A006 by H. Andernach
() and the ADS documentation prepared in
collaboration with Carolyn Stern Grant ()."
(End) Patricio Ortiz [CDS] 30-Mar-1999