In general, STIPS expects catalogues to be formatted in the IPAC table format. This format was chosen both because columns may be given names, data types, and unit values; and because IPAC supports keyword/value metadata which allows STIPS to determine what type of catalogue it has been given. STIPS uses the astropy.table module to handle catalogue input and output. Note that, as of astropy 1.0, table metadata is not necessarily preserved when writing an IPAC table, but the resulting text file may be edited, and keyword/value pairs may be added to it, after the table itself has been written.
STIPS currently understands six catalogue formats, named 'phoenix', 'bc95', 'internal', 'mixed', 'multifilter', and 'generic'. The required metadata and columns are shown below.
A 'phoenix' catalogue is intended to include stars drawn from the phoenix simulator (as translated into a grid by pysynphot). A phoenix catalogue is a point-source catalogue which specifies each source by:
In order to identify the catalogue as a phoenix catalogue, the following metadata must be present:
During the observation, this catalogue will be converted to an internal format, with any necessary additional metadata added at this point. Stellar count rates will be generated from the Phoenix grid.
A 'bc95' catalogue is intended to include galaxies created from the Bruzual and Charlot Isochrone Synthesis Spectral Evolutionary Code (December 1995 version). A bc95 catalogue is an extended-source catalogue, which specifies each source by:
In order to identify the catalogue as a bc95 catalogue, the following metadata must be present:
During the observation, the catalogue will be converted into an internal format, with any necessary additional metadata added at this point. Galaxy spectra will be generated from the atlas, and count rates derived through pysynphot observation of the generated spectrum.
An 'internal' catalogue is intended to include either point or extended sources, but is limited to a single filter. It must contain the following columns:
In order to identify the catalogue as an internal catalogue, and in order to use it for the observation, the following metadata must be present:
This catalogue will not be converted during observation, except that the RA and DEC values will be converted into X and Y values, and point sources not falling on the detector will be discarded.
A 'mixed' catalogue is identical to an internal catalogue, except that it contains one additional column:
In order to identify the catalogue as a mixed catalogue, the following metadata must be present:
This catalogue will have its flux values converted to counts/s, and will then be treated as an internal catalogue.
A 'multifilter' catalogue is identical to an internal catalogue, except that it does not have a filter specified in its metadata and, instead of having a Flux column, it has one or more columns, each named after an available filter, that indicate the source count rate in that filter. The appropriate filter's count rate will be renamed as 'flux' as the catalogue is converted to internal format. The 'type=multifilter' metadata must be present.
A 'generic' catalogue is a point-source catalogue with the following columns:
No specific metadata is required, other than that, if this catalogue has a 'type' metadata field, it must not be equal to any of the above values.