Source Lists

by Gustaaf Van Moorsel last modified Sep 21, 2017 by Lorant Sjouwerman


Text files with source lists can be imported into the SCT (and PST) if they use the following syntax. Every line containing any source information in the file must define a separate source as:


The text file should only contain lines formatted as above, or lines that are known to be ignored by the parser (i.e., empty or whitespace-only lines and comment lines starting with a #-hash). An (optional) exception is if the very first line is starting with a *-star; the string after the star will replace the default source catalog name. Start with the catalog name syntax line before any source syntax line or any comment line or this source catalog name will not be picked up (and an "Unnamed Catalog" results):

* Source catalog name in the SCT
# this is a line with a comment and the previous line is the syntax used to include all sources into a non-default
# (the catalog name line will be ignored by the PST when uploading this file)
# the rest of the source list file contains source lines mandated as above and other ignored lines
<source1 line>
<source2 line>

Every data line must have ten semi-colons (;) , including the one after the final calibrator field. Details and possible (predefined) values per field are described here:

sourceName Mandatory, single value
Unique name for the source, free-format text. Multiple lines with the same source name, longitude, latitude and velocity information (below) will end up as a single source entry
groupNames Optional, unlimited number of comma-separated values
Group(s) or sub-catalog(s) to which this source belongs, free-format text. If no group name is given the source will be listed in the main (top-level) catalog only
coordSystem Optional, single value (defaults to equatorial), not case-sensitive
Coordinate system in which longitude and latitude angles below are defined, typically Equatorial for source coordinates in RA and Dec. (the default). Valid options are: Ecliptic, Equatorial, Galactic. Sources converted to other, e.g., equatorial coordinates will show an asterisk with the converted coordinates in the catalog
epoch Optional, single value (defaults to J2000), not case-sensitive
Epoch for which longitude and latitude angles below are defined, valid options are: B1950, J2000
longitude Mandatory, single value
An East-West angle, typically Right Ascension. Valid options are a numerical value in decimal degrees or a sexagesimal colon-delimited value in hh:mm:ss.sss. . . (with or without leading zeros) for hours : minute : seconds. Either form may be preceded by the plus (+) or minus (−) sign
latitude Mandatory, single value
A North-South angle, typically Declination. Valid options are a numerical value in decimal degrees or a sexagesimal colon-delimited value in . . (with or without leading zeros) for degrees : arcminute : arc-seconds. Either form may be preceded by the plus (+) or minus (−) sign
refFrame Mandatory in combination with convention and velocity, single value, not case-sensitive
The reference frame in which the velocity below should be interpreted. If any of refFrame, convention or velocity is specified, all three must be specified to make sense. Leave all three blank if no velocity information should be included in the source properties. Useful valid options with their abbreviations are: Barycentric (Bary), LSR Kinematic (LSR or LSRK), Topocentric (Topo)
convention Mandatory in combination with refFrame and velocity, single value, not case-sensitive
The frame definition in which the velocity below should be interpreted. Useful valid options are: Optical, Radio, Redshift
velocity Mandatory in combination with refFrame and convention, single value
A decimal number, optionally preceded by the plus (+) or minus (−) sign, to express the source velocity in km/s, or to express the source redshift in z if the convention above is Redshift
calibrator Optional single value (defaults to N), not case-sensitive
A value of Y or N to indicate whether a source is to be used as calibrator. The SCT will ignore this field; it is retained to maintain compability with the PST and other tools. Instead, calibrators for the VLA are identified with scan intents in the OPT.


To ingest a text file with a source list, navigate to the SCT. Select from the menu FILE - IMPORT and then PST for the import format. After providing a file to import, a new catalog with the default name “[Unnamed Catalog]” will be created. If the imported sources need to be included in a different catalog, or a different catalog group, use the general copy/paste method of the OPT web application to move the sources around. Alternatively, change the name of the new unnamed catalog in the SCT using the "Properties" tab of that catalog if a name was not specified with a *-star line.

Source List Examples (in SCT/PST format)

Minimalist. Source name and coordinates only, default coordinate system, epoch and unspecified velocity:

<some_name> <4 times ";"> <RA_j2000> ; <Dec_j2000> <5 times ";">

Explicit. Same data as minimalist, above, but with coordinate system and epoch stated in long form, and spaces for ease of reading:

J0433+0521; ; equatorial; J2000; 04:33:11.095535;  05:21:15.619420; ; ; ; ;
J1119−0302; ; equatorial; J2000; 11:19:25.3 ; −03:02:51.32 ; ; ; ; ;

Full. All fields are specified, starting by naming the catalog "MyPrivateList" in which these sources should appear (instead of the default "Unnamed Catalog"); multiple values in those fields that allow it, with spaces in source and group name, some case-preserved and case-ignored variable names, and with optional trailing comma in velocities.

* MyPrivateList
# This is my private list of secret sources..
Secret Source; My Recipes, Private; equatorial; J2000; 12:34:56.789; 87.65432; lsR; Optical; −98.6,; y;