[ CATS home ] [ Back to CATS list ] [ ftp ]

1991ApJS...75....1Becker

A new catalog of 53522 4.85 GHZ sources

Becker, R. H., White, R. L., and Edwards, A. L.

Abstract

A catalog of 53522 4.85 GHz sources between 0 and 75^o declination has been generated from observation taken with the NRAO Green Bank 300 foot (91m) telescope. The flux limit of the catalog is dependent on confidence radius of ~50". Spectral indices have been calculated for 29051 sources which have counterpart in the Texas 365 MHz northern sky survey.

Catalog constuction

The observations were made in 1987 October. The resulting data were gridded into 285 1024x1024 FITS imagis with 40" pixel size. The rms noise in the images varied from 5 to 8 mJy. The images has an angular resolution of ~3.5'. Sources with peak fluxes brighter than 70 Jy were truncated in the images, so they usually have been omitted from our catalog.
The extraction of the source catalog from the images limited smaller than ~5' in diameter. All source identification were based on high filtered images (each pixel - surrounding 15 x 15 pixel area median value).
The catalog of 53522 sourecs is given in Tables 3 - 5 for the declination 40, 20 - 40 and 20^o. There are 3279 extended sources in the catalog.
Distribution version, 4 September 1990
This is a brief description of the format of the distribution version of the 6 cm Northern Sky Catalog of Becker, R. H., White, R. L., and Edwards, A. L. (1991, Ap.J.Suppl., 75, 1). For more details see the paper.

The catalog is in an ascii file with 44 characters per record. It can be read with the following Fortran statements: 

      character name*10, decsgn*1, extflg, widflg
      integer rahh, ramm, decdd, decmm, decss, flux
      real rass, spind
      read(10,1) name, rahh, ramm, rass, decsgn, decdd, decmm, decss,
     &   flux, extflg, spind, widflg
1     format(a10,1x,i2, 1x, i2, 1x, f4.1, 1x, a1, i2, 1x, i2, 1x, i2,
     &   i6, a1, 1x, f4.1, a1)

Column Variable Format  Description
------ -------- ------  -----------
 (1)     NAME    A10    6cm Name, constructed from RA, Dec HHMM+DDMM with
                          A or B added at end if needed to make name unique
 (2)     RAHH    I2     Hours of right ascension (1950)
 (3)     RAMM    I2     Minutes of RA
 (4)     RASS    F4.1   Seconds of RA
 (5)     DECSGN  I2     Sign of declination
 (6)     DECDD   I2     Degrees of declination
 (7)     DECMM   I2     Minutes of declination
 (8)     DECSS   I2     Seconds of declination
 (9)     FLUX    I6     4.85 GHz flux (mJy)
(10)     EXTFLG  A1     "*" if source is extended, else blank
(11)     SPIND   F4.1   Spectral index between 4.85 GHz and 0.365 GHz (flux
                          from Texas survey, Douglas et al., private comm.),
                          blank if not detected at 0.365 GHz
(12)     WIDFLG  A1     "*" if separation between 4.85 GHz and 0.365 GHz
                          positions is greater than 100 arcsec, else blank

Here are a few sample lines from the catalog:

123456789 123456789 123456789 123456789 1234
  Name     HH MM SS.S SDD MM SS FFFFFE SS.SW
0000+1833  00 00  4.0 +18 33 23    66  -0.9 
0000+1549  00 00  5.9 +15 49 12    72       
0000+7459  00 00 17.5 +74 59 18    47       
0000+5729  00 00 42.8 +57 29 16    64  -0.7*
0001+0343  00 01  6.5 +03 43 20   107*
up Back to begining