gtpulsardb Help File
Creates, filters, and/or combines pulsar ephemerides database files.
gtpulsardb is a utility for manipulating and accessing databases containing pulsar ephemeris data. Using this tool, one can accept input from any number of FITS files in the Fermi (formerly GLAST) D4 format, and/or simple text files containing pulsar data. These input pulsar ephemerides can be filtered by pulsar name and other criteria, and the results stored in a new Fermi D4 FITS file.
In the following example, the tool filters an ephemerides file to extract only ephemerides for a particular pulsar as follows:
The name supplied in the example was simply "Crab", but in general the "B-name" or "J-name" may be used as well as common names such as "Crab" or "Vela". Colloquial names and B-names are looked up using the ALTERNATIVE_NAMES extension to obtain the correct J-name, which is then used to look up ephemerides in the SPIN_PARAMETERS and/or ORBITAL_PARAMETERS.
In order to merge two or more ephemerides files, it is necessary to supply more than one file name through the psrdbfile parameter. This is done using the "at-file" syntax familiar to
Pulsar Ephemeris Database File
A pulsar ephemeris database file is a FITS file or a text file in a Fermi-specific format, and contains a set of pulsar ephemerides to be used in a temporal analysis of Fermi data. When so specified, the pulsar analysis ScienceTools load pulsar ephemerides from pulsar ephemeris database files, and use them in their tasks. A pulsar ephemeris database file can be created, filtered, and combined by the gtpulsardb tool. Pulsar ephemerides for the Fermi LAT pulsars and timing models associated with various Fermi publications are also available on the FSSC's Gamma-ray Pulsar Timing Database page.