PulsarAstronomy.net
The Pulsar Astronomy Network

The most simple pulsar data format is the ephemeris.
This is the parameters used in the timing model.
Ephemerdies come as text files with a .eph or .par extension.

There appears to be no formal specification of what parameters are used in these files, although a loose standard has developed, with the following common parameters.


|| border=1
||!Parameter ||!Units ||!Description ||!Aliases
|| PSRJ || String || Pulsar JName ||
|| RAJ || sex-hr || Right Asscention (J2000) ||
|| DECJ || sex-deg|| Declination (J2000) ||
|| PEPOCH || MJD || Period Epoch ||
|| F0 || Hz || Fundemental frequency of the PSR || F (sometimes P/P0, the period)
|| F1 || Hz/s || First derivitive of rotational freq ||
|| F2 || Hz/s/s || Second derivitive of rotational freq ||
|| POSEPOCH || MJD || Position Epoch ||
|| DM || pc/cm3 || Dispersion Measure ||
|| START || MJD || Time the eph is valid from ||
|| FINISH || MJD || Time the eph is valid till ||
|| BINARY || String || The binary model used (if any) ||
|| EPHVER || Integer|| The eph version ||


The parameters for the binary motion are dependent on the binary model used.

For the '''BT''' model:

|| border=1
||!Parameter ||!Units ||!Description ||!Aliases
|| A1 || ltsec || projected semimajor axis ||
|| ECC || || Eccentricity of the orbit || E
|| T0 || MJD || Epoch of periastron ||
|| PB || days || Orbital Period ||
|| OM || deg || Longitude of Periastron ||


The files are tab or whitespace seperated with a single line for each keyword.
Note that exponentials can be writen with a standard 'e' notation, or the rather more strange 'D' notation.
e.g.
PSRJ 1722-2210
F0 1.23234234
F1 2.34567D-02


The files produced by tempo and psrtime should be compatable.
tempo2 can read tempo files, with the -tempo1 switch.
tempo2 files are not backwards compatible to psrtime.

Catagories: [[!Data Formats]]

Catagories: [[!dataformats]]

!!Ephemeris Files

(!dataformats)

!!Ephemeris Files