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VIII/21 6C Survey of Radio Sources II (6CSRSII; Hales+ 1988)
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The 6C Survey of Radio Sources - II.
The Zone 30 Degrees < Dec < 51 Degrees, 09h 30m < RA < 17h 30m
Hales S.E.G., Baldwin J.E., Warner P.J.
<Mon. Not. R. Astron. Soc. 234, 919 (1988)>
=1988MNRAS.234..919H
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ADC_Keywords: Radio sources; Surveys
Summary:
This catalogue contains the second section of the 6C Cambridge survey
of radio sources at 151 MHz, covering the region from 30 deg to 51 deg
in declination and between 8h 30m and 17h 30m in right ascension. The
survey has an angular resolution of 4.2 arcmin x 4.2 arcmin x cosec(dec).
Data include the source positions (B1950), peak flux density, integrated
flux density, contour map panel number and contour map field names.
Its limiting flux density depends weakly on right ascension and
strongly on declination and is 190 mJy in the central part of the
declination strip but rises to over 400 mJy near its northern and
southern boundaries. This part of the survey contains 8278 sources,
covering an area of 2030 square degrees.
Description:
"The 6C Survey of Radio Sources - II. The Zone 30 deg. < Dec < 51 deg.,
08h 30m < RA < 17h 30m" (6CSRSII) contains a compilation of radio
source observations made with the use of an (non- tracking)
Earth-rotation aperture synthesis telescope comprising many small
aerial arrays on an east-west baseline operating at 151 MHz. This paper
is the second in a series: Details on the design and operation of the
telescope and the reduction of the survey were first discussed in
Baldwin et al. (1985). The third paper in this series was published in
Hales et al. (1990) and the fourth paper in the series was published in
Hales et al. (1991).
The catalogue contains a listing of 8278 radio sources ordered by
increasing right ascension from 8h 30m to 17h 30m . The survey is
centered on a declination of 41 deg and includes from declination 30
deg to 50 deg. Five fields have been included in this survey:
0940+41, 1120+41, 1300+41, 1440+41, and 1620+41.
Attenuation corrections were applied to all flux densities and maps
using tables derived for each synthesis. Flux densities are on the
scale of Roger, Bridle, and Costain (1973) (RBC). The authors believe
the flux density scale is consistent with the RBC scale to within
+/-5%. See 6CSRSII for details on source selection criterion and error
analysis.
Source positions have been systematically adjusted (by 0.6s in right
ascension and by up to 10 arcsec in declination) to agree with known
positions of bright sources. The residual rms scatter in the corrected
positions of the reference sources relative to their true positions is
estimated to be +/- 4 to 5 arcsec in each coordinate. See 6CSRSII for
details.
Note that this file only contains the catalogue of radio sources. It
is intended to be used with the radio maps originally published on
microfiche in Hales, Baldwin and Warner (1988). The source lists and
FITS format maps for the four regions of the 6C survey published t-date
have been placed on a CDROM entitled "Images from the Radio
Universe", which is available from the address below. A nominal
fee may be charged for such requests.
Prof. Jim Condon
NRAO
Edgemont Road
Charlottesville, Virginia 22903-2475
Structure:
The File as a Whole
"The 6C Survey of Radio Sources - II. The Zone 30 deg < Dec <51 deg,
08h 30m < RA < 17h 30m "consists of a single fixed-block file of 8278
50-byte records. The original file contained 80-byte records. Detailed
descriptions of some of the fields in the file are given in the
following sections.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This File
6csrsii.dat 43 8278 Catalog Data
6csrsii.tex 74 194 LaTeX Document
adc.sty 68 38 ADC Style File
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See also:
http://imagelib.ncsa.uiuc.edu/project/document/95.SH.02 : FITS images
of the survey available from the NCSA Astronomy Digital Image Library
Byte-by-byte Description of file: 6csrsii.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension (B1950)
4- 5 I2 min RAm Right ascension (B1950)
7- 10 F4.1 s RAs Right ascension (B1950)
12- 13 I2 deg DEd Declination (B1950)
15- 16 I2 arcmin DEm Declination (B1950)
18- 19 I2 arcsec DEs Declination (B1950)
21- 25 F5.2 Jy PeakFlux *Flux density (peak)
27- 31 F5.2 Jy IntFlux *? Flux density (integ.)
32 A1 --- n_IntFlux *Integrated Flux flag
34- 35 I2 --- map_num *Contour map panel number
37- 43 A7 --- field *Contour map field name
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Note on PeakFlux:
Flux density (peak): Source peak flux density at 151 MHz.
Note on IntFlux:
Flux density (integrated): Source integrated flux density at 151 MHz.
Integrated flux densities were carried out for sources with
apparent flux densities above 483 mJy. The integration was
carried out to a limiting level of 10% of the fitted peak (or for 103
mJy for sources having apparent flux densities < 1.03 Jy). Note that
for unresolved sources the integrated flux value can fall below the
peak value.
Note on n_IntFlux:
Integrated flux flag: If the column is marked with a dash (-), the
peak flux was not strong enough to calculate the integrated flux. If
the column is marked with an asterisk (*), the peak flux was strong
enough to qualify for integration, but it has been integrated into a
brighter adjoining peak.
Note on map_num:
Contour map panel number: This column contains the panel number of the
contour map in which the source appears in the survey. Each map field
is divided into 32 contour panels. The panel number and the map field
name tell the user where to look up the source of interest in the
published contour map.
Note on field:
Contour map field name: This column contains the name of the
field in which the source appears. There are five fields in this
survey: 0940+41, 1120+41, 1300+41, 1440+41, and 1620+41. The panel
number and the map field name tell the user where to look up the source
of interest in the published contour map.
History:
"The 6C Survey of Radio Sources - II. The Zone 30 deg < Dec <51 deg,
08h 30m < RA < 17h 30m " was received by the Astronomical Data Center
(ADC), NASA Goddard Space Flight Center, from Dr. Heinz Andernach.
The catalog was originally submitted by the first author, Dr.
Sally Hales.
The integrated flux flag column was added by the ADC/CDS by extracting
the character information from the Integrated flux density column.
This was done to avoid mixing character and numeric information in
the same column.
References:
Baldwin, J.E., Boysen, R.C., Hales, S.E.G., Jennings, J.E., Waggett,
P.C., Warner, P.J. and Wilson, D.M.A. 1985, MNRAS, 217, 717
Hales, S.E.G., Baldwin, J.E. and Warner, P.J. 1988, MNRAS, 234, 919
Hales, S.E.G. 1990, MNRAS, 246, 256
Hales, S.E.G. 1991, MNRAS, 251, 46
Roger, R.S., Bridle, A.H. and Costain, C.H. 1973, AJ, 78, 1030
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(End) N.A. Oliversen and N.P.M. Kuin (ADC/SSDOO/NASA) 10-MAY-1995