Detailed Description of Catalogue VIII/16/

VIII/16     Molonglo Reference Catalogue of Radio Sources (Large+ 1991)
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Molonglo Reference Catalogue of Radio Sources
    Large M.I., Cram L.E., and Brugess A.M.
    <The Observatory, 111, 72 (1991)>
     =1991Obs...111...72L     (SIMBAD/NED RefCode)
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ADC_Keywords: Radio sources

Description:
    "408-MHz survey observations made with the Molonglo Radio Telescope
    have been used to prepare a catalogue of 12 141 discrete sources of
    listed flux density >= 0.7 Jy. The survey covers 7.85 sr of the sky
    defined by +18.5 (deg) >= dec(1950) >= -85.0 (deg), mod(b) >= 3 (deg).
    A few sources beyond the declination limits are also included. The
    catalogue comprises celestial coordinates with standard error
    typically lying between 3 and 10 arcsec and 408-MHz flux densities
    with standard error typically lying between 4 and 10 per cent.
    Galactic coordinates, notes on source morphology and cross-references
    to the Parkes Catalogues are included. The overall source density is
    1500/sr, corresponding to 0.001 per beam area. There are 7347 sources
    of listed flux density >= 1.00 Jy, at which level the catalogue is
    substantially complete. The reliability is believed to be better than
    99.9 per cent." The MRC was re-issued in 1990 with the original B1950
    coordinates supplemented by J2000 values, and an additional
    cross-reference flag `J' added to denote (extended) sources imaged at
    843-MHz by P.A. Jones. No other alterations were made to the original
    release. The MRC is now available on 5.25 inch, 1.2 Mbyte MS-DOS (IBM)
    floppy disk (0.5 inch magnetic tape is also available, but is not the
    preferred medium). In the floppy disk format, simple software is
    provided to facilitate use of the catalogue on a PC computer.

File Summary:

      

  FileName      Lrecl  Records   Explanations

ReadMe             80        .   This file
mrcj2000           87    12141   Catalog Data
mrc.for            75      724   F77 code to read catalog by L. Cram (1990)
mrc.exe            80      693   MS-DOS executable from mrc.for


Byte-by-byte Description of file: mrcj2000

   Bytes Format  Units   Label    Explanations

   1-  9  A9     ---     Bname   *Recommended IAU name of the source based on
                                  B1950 equinox.
  11- 12  I2     h       RAh      Right ascension (hours) in B1950 equinox
  14- 15  I2     min     RAm      RA (minutes) in B1950 equinox
  17- 20  F4.1   s       RAs      RA (sec) in B1950 equinox
      22  A1     ---     DE-      Declination sign
  23- 24  I2     deg     DEd      DEC in degrees in B1950 equinox
  26- 27  I2     arcmin  DEm      DEC in arcminutes in B1950 equinox
  29- 30  I2     arcsec  DEs      DEC in arcseconds in B1950 equinox
  32- 33  I2     h       RAh2000  Right ascension (hours) in J2000 equinox
                                   (Converted from B1950 using the STARLINK
                                    program COCO)
  35- 36  I2     min     RAm2000  RA (minutes) in J2000 equinox
  38- 41  F4.1   s       RAs2000  RA (seconds) in J2000 equinox
      43  A1     ---     DE-2000  Declination sign
  44- 45  I2     deg     DEd2000  DEC in J2000 equinox
  47- 48  I2     arcmin  DEm2000  DEC in J2000 equinox
  50- 51  I2     arcsec  DEs2000  DEC in J2000 equinox
  52- 54  F3.1   s     e_RAs2000  Standard error in RA (in seconds of time)
      55  A1     ---     n_RAs    [*] scattering flag (1)
  56- 57  I2     arcsec e_DEs2000  Standard error in Dec (in seconds of arc)
      58  A1     ---     n_DEs    [*] scattering flag (1)
  59- 65  F7.2   Jy      S408     Flux density
  66- 69  F4.2   Jy      e_S408   Standard error
      70  A1     ---     n_S408   [*] scattering flag (1)
  71- 73  A3     ---     Mflag   *[ AECMN] *Morphology flags
  74- 76  A3     ---     Cflag   *[ CJMPRST] Cross-reference flags.
  77- 81  F5.1   deg     GLON     [0,360] Galactic longitude
  82- 87  F6.1   deg     GLAT     Galactic latitude

Note (1): A `*' indicates that the values obtained from two or more
          independent transits are scattered more than expected.
Note on Bname:
    The first four characters are the hours and minutes of right
    ascension, and the last four the signed declination in tenths of a
    degree (unrounded). Column 9 contains the letters A, B, etc. denoting
    sources having the same eight-character IAU designation but decreasing
    flux density.
Note on Mflag: the Morphology flags are:
  blank - no clear evidence of departure from point
  A     - Source with small-scale structure
  E     - Extended source
  C     - Complex extended source
  M     - Multiple sources (within 8 arcmin of another)
  N     - Weak neighbouring sources
Note on Cflag:
  J  -  See Jones (1989, PhD, Sydney; published =1992ApJS...80..137J)
        the 'J' is always in byte 74
  P  -  Source lies within 2 arcmin of a Parkes source (catalog VIII/15)
  T  -  Discussed in the original MNRAS MRC paper (1981MNRAS.194..693L)
  S  -  See Schilizzi and McAdam (1975MmRAS..79....1S)
  M  -  See Clarke et al. (1976AuJPS..40....1C)
  C  -  See Cameron (1971MNRAS.152..439C)
  R  -  See Robertson (1973AuJPh..26..403R)
  Two flags at most are used in Cols 75-76, with P>T>S>M>C>R.


Data structure:
  The machine-readable MRC is provided as 12141 ASCII records, each
  of fixed length 87 bytes (each followed by CR,LF). The first line is
  listed below, with `x' in positions that may be occupied by characters
  but are blank in the first record :
  ===========================================================================
  1        10        20        30        40        50
  |        |         |         |         |         |
  0000-506x 00 00 09.2 -50 41 31 00 02 42.5 -50 24 49x.3xx4xx

  60        70        80
  |         |         |
  xx1.28x.06xxxxxpx-64.9 321.4
  ===========================================================================

FORTRAN code to read MRC:
  FORTRAN 77 source is included (mrc.for) to allow menu-driven reading of
  the MRC as provided here. The FORTRAN program is self-explanatory. It
  expects to find the MRC ASCII data file in the current directory and with
  the name MRCJ2000. An executable version of this FORTRAN code has been
  produced (using Microsoft FORTRAN Version 5, with a library which uses a
  co-processor should one be available) and may be invoked on an IBM AT or
  compatible by setting the correct current directory and typing `MRC'. The
  program will run faster if the source and data are placed on a hard disk.

Historical Notes:
  The original MRC was published in Mon. Not. R. astr. Soc., Vol 194,
  pp 693-704 and Microfiches MN 194/1. (1981MNRAS.194..693L)
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(End)   F. Ochsenbein [CDS], C.-H. Joseph Lyu [Hughes STX/NASA]      01-Aug-1995