gtpspec Help File
gtpspec searches for pulsations in a relatively wide range of frequencies. It uses the Discrete Fast Fourier Transfer (FFT) technique to compute power spectrum density. This tool is suitable for a so-called blind period search, in which data are examined for pulsations at any frequency. Ephemeris information can be given in one of the following forms:
The example below shows how to perform a pulsation search in the simplest case, where one can assume no significant frequency variations exist throughout the observation. The time origin of
This command produces an output message that describes the search criteria and explains the search result. A plot will also be produced.
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 Science Tools 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.