Source catalogs

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Source catalogs

ASTRO uses source catalogs, that are selected by the CATALOG name command. File extension may be omitted when specifying the file name, the default is .sou. The catalog format is that used at the Plateau de Bure and Pico Veleta telescopes.

Catalogs in the old OBSINP input format, used at the IRAM 30-m Pico Veleta telescope until 2006, may also be read. The command is then CATALOG /VELETA. In that case, the input file (default extension .cat) is read and converted to the standard format; a file with the same name but extension .sou is created in the current directory.

In the ASTRO catalog 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 next keyword (equinox) 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 hh:mm:ss.sss or dd.ddd or hh:mm.mmm.
- Latitude-like coordinate: in degrees, or hours for EQ and DA (same format as above).
- Velocity type: alphabetic code, can be 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).
- Spectral index (optional).

A second catalog (known as the “ALTERNATE”catalog ) may also be defined, using CATALOG Name /ALTERNATE. 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 the project sources in the main catalog, and pointing sources or phase calibrators in the ALTERNATE catalog.

Example of catalog:

      IRC+50096               3:22:59.000    47:21:19.00    LS -17.2
      CRL618                  4:39:34.000    36:01:16.00    LS -21.3
      IRC+10216               9:45:14.800    13:30:40.50    LS -27.0
      CIT6                    10:13:11.000   30:49:17.00    LS -1.8
      IRC-10236               10:14:35.000   -14:24:31.00   LS 3.3
      YCVN                    12:42:47.000   45:42:48.00    LS 21.7
      IRC+10420               19:24:26.700   11:15:11.00    LS 75.0
      CRL2688                 21:00:19.900   36:29:45.00    LS -36.0
      NGC7027                 21:05:09.400   42:02:03.00    LS 24.8
      RCAS                    23:55:51.700   51:06:36.00    LS 22.0
      OH26.5+0.6              18:34:52.500   -5:26:37.00    LS 27.0
      OH104.9+2.4             22:17:42.500   59:36:16.00    LS -28.0
      MUCEP88       EQ 1988.5 21:43:09.300   58:43:37.00    LS 0
      ALIRA         EQ 2000.0 18:36:56.200   38:47:01.00    LS 0.