Catalogs of Sources

ASTRO uses as default the catalog format for Plateau de Bure. The catalog is selected by command CATALOG name , where name is the file specification for the catalog. File extension may be omitted, default is .SOU. Catalogs in the OBSINP input format, in use at Pico Veleta for the IRAM 30-m telescope, may also be used; the command is then CATALOG /VELETA . In that case, the input file (default extension .CAT) is read and converted to the standard Plateau de Bure format; a file with the same name and extension .SOU is created in the current directory.

In the Plateau de Bure format each source uses one line of the catalog file. Each line should contain the following consecutive keywords (some may be omitted):

• Source name field:
  The source name field is a composite item which can accomodate several names for a single source. Names should be separated by a vertical bar | with no embedded spaces, e.g.:

  B0415+379|3C111
  

  Each name must have at most 12 characters.
• Coordinate system: 2 characters, optional, may be:
  • EQ for equatorial coordinates. If EQ is given explicitely, then the epoch keyword is mandatory.
  • GA for Galactic II coordinates.
  • EC for J2000 Ecliptic coordinates
  • HO for horizontal coordinates
  • DA for equatorial, present-day coordinates.
• Epoch: needed for equatorial coordinates after EQ keyword.
• Longitude-like coordinate: in degrees, except for EQ and DA where it should be in hours. Format is like hh:mm:ss.sss or dd.ddd or hh:mm.mmm ...
• Latitude-like coordinate: in degrees, same format as above.
• Velocity type: alphabetic code , such as LSR, HELIO or EARTH.
• Velocity: in km/second, in the corresponding reference frame (LSR, Heliocentric, or local. Default is zero.
• Intensity type: Either FLUX or MAGNITUDE (optional)
• Intensity: Either the Flux in Jansky or the magnitude (optional) The flux can be followed by a spectral index.

A second catalog (known as the ``ALTERNATE''catalog ) may also be defined: commands SOURCE , HORIZON  and CONVERT  will take sources from this alternate catalog if used with the /ALTERNATE option. This enables easy switching between two classes of objects: for instance your project sources in the main catalog, and pointing sources, or phase calibrators, in the ALTERNATE catalog.