NAME gtpphase - Computes a pulse phase for each event in input event file(s), and writes it to a FITS column in the file(s). USAGE gtpphase evfile scfile psrdbfile psrname ephstyle ephepoch timeformat timesys ra dec phi0 f0 f1 f2 p0 p1 p2 DESCRIPTION This tool operates on input event file(s) to compute a pulse phase for a photon arrival time of each event, and writes it to the PULSE_PHASE column (by default) of the event file(s). Ephemeris information can be given in one of the following forms: 1) manually input the source (pulsar) location (for the barycentric correction), pulse frequency or period, and related information, and 2) automatically extracted from a pulsar ephemerides database, available online. If necessary, this tool reads the spacecraft orbit file and performs the barycentric correction and the binary demodulation to each photon arrival time on the fly. PARAMETERS evfile [file name] Name of input event file, event file format or equivalent. scfile [file name] Name of input spacecraft data file, S/C format or equivalent. psrdbfile [file name] Name of pulsar ephemerides database file, in Fermi (formerly GLAST) D4 FITS format (See PULSAR EPHEMERIS DATABASE FILE). Multiple files may be combined by listing them in a text file, one per line, and supplying the list file name preceded by an @ sign. If psrdbfile is NONE (case-insensitive), no ephemeris is loaded from a file. psrname = ANY [string] Name of the pulsar, used to select only ephemerides valid for a particular pulsar. ephstyle = DB [enumerated string (DB|FREQ|PER)] Method to specify how the ephemerides will be supplied. If ephstyle is DB, a pulsar database file in Fermi (formerly GLAST) D4 FITS format will be used. If ephstyle is FREQ (PER), the user will supply values for the frequency (period) and its derivatives at the time given by the epoch parameter. ephepoch = 0. [string] Reference epoch of the ephemeris that will be manually specified. This parameter only has effect if ephstyle is FREQ or PER. timeformat = FILE [enumerated string (FILE|MJD|FERMI|GLAST)] String describing the representation used for ephepoch parameter. If FILE is chosen, the time format specified in the input event file header will be used. timesys = FILE [enumerated string (FILE|TAI|TDB|TT|UTC)] String describing the time system used for ephepoch parameter and the following ephemeris parameters: phi0, f0, f1, f2, p0, p1, and p2. In other words, ephemeris computaions with those parameters will be performed in the time system specified by this parameter. If FILE is chosen, the time system specified in the input event file header (TIMESYS keyword) will be used. ra [double] Right Ascension of point source in degrees for which to perform the barycentric correction. This parameter only has effect if ephstyle is FREQ or PER. dec [double] Declination of point source in degrees for which to perform the barycentric correction. This parameter only has effect if ephstyle is FREQ or PER. phi0 = 0. [double] Phase offset at this ephepoch for a user-supplied ephemeris. This parameter only has effect if ephstyle is FREQ or PER. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. f0 = 1. [double] Value of the frequency at the time given by the epoch parameter in the units of s^(-1). This parameter only has effect if ephstyle is FREQ. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. f1 = 0. [double] Value of the first time derivative of the frequency at the time given by the epoch parameter in the units of s^(-2). This parameter only has effect if ephstyle is FREQ. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. f2 = 0. [double] Value of the second time derivative of the frequency at the time given by the epoch parameter in the units of s^(-3). This parameter only has effect if ephstyle is FREQ. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. p0 = 1. [double] Value of the period at the time given by the epoch parameter in seconds. This parameter only has effect if ephstyle is PER. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. p1 = 0. [double] Value of the first time derivative of the period at the time given by the epoch parameter (dimension-less). This parameter only has effect if ephstyle is PER. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. p2 = 0. [double] Value of the second time derivative of the period at the time given by the epoch parameter in the units of s^(-1). This parameter only has effect if ephstyle is PER. Note that ephemeris computations using this parameter will be performed in the time system specified by timesys parameter. (tcorrect = AUTO) [enumerated string (NONE|AUTO|BARY|BIN|ALL)] Set of arrival time corrections to apply. If tcorrect is NONE, no corrections will be applied. If tcorrect is BARY, only the barycentric correction will be applied. If tcorrect is BIN or ALL, an appropriate orbital ephemeris is searched for in the pulsar database, and if found, binary demodulation will be applied after the barycentric correction, and if not, an error will be generated. If tcorrect is AUTO, the barycentric correction will be applied, then the binary demodulation will be applied only when an orbital ephemeris is available in the pulsar database. (solareph = JPL DE405) [enumerated string (JPL DE200|JPL DE405)] Solar system ephemeris for the barycentric correction. (matchsolareph = ALL) [enumerated string (NONE|EVENT|PSRDB|ALL)] String that controls whether to use the name of the solar system ephemeris given by the solareph parameter to check the input event data file and to select ephemerides in the pulsar database. If matchsolareph is EVENT, all the input event files are required to use the same solar system ephemeris for the barycentric correction as the one given by the solareph parameter, and an error will be generated if otherwise. Such an error may occur when an input event data file has already been applied the barycentric correction with a different solar system ephemeris. If matchsolareph is PSRDB, the string given by the solareph parameter is used to select the ephemerides. If matchsolareph is ALL, both actions for the EVENT option and the PSRDB option will be taken. If matchsolareph is NONE, no selection will be performed. (angtol = 1.e-8) [double] Angular tolerance in degrees in comparison of two source positions, one for which the barycentric correction is performed, and another given by RA_NOM and DEC_NOM header keyword of an event file to which the barycentric correction has already been applied. This parameter only has effect if the barycentric correction has been applied to an input event data file. If the two source positions are separate from each other by this amount or less, then they will be considered to be the same position. Otherwise an error will be generated. The sign of the parameter value is ignored. For example, setting angtol=-1.0 results in giving angular tolerance of 1 degree. (evtable = EVENTS) [string] Name of the FITS table containing the event data. (timefield = TIME) [string] Name of the field containing the time values for temporal analysis. (sctable = SC_DATA) [string] Name of the FITS table containing the spacecraft data. (pphasefield = PULSE_PHASE) [string] Name of the output column to contain the assigned pulse phase. (pphaseoffset = 0.) [double] Global offset applied to all assigned pulse phases. This may be used to shift the entire pulse profile. Note that this offset will be applied regardless of the source of the ephemeris used, whereas phi0 is used only when ephstyle is FREQ or PER. (leapsecfile = DEFAULT) [file name] Name of the file containing the name of the leap second table, in OGIP-compliant leap second table format. If leapsecfile is the string DEFAULT, the default leap-second file (leapsec.fits), which is distributed with the extFiles package, will be used. (reportephstatus = yes) [bool] If reportephstatus is yes, the application will examine the input pulsar ephemeris database, and report findings which may affect the requested ephemeris computations. If reportephstatus is no, it will not report any ephemeris status. (chatter = 2) [integer, min=0, max=4] This parameter fixes the output verbosity: no screen output (0), nominal screen output (2), maximum verbosity (4). (clobber = yes) [boolean] Overwrite or do not overwrite existing output files. (debug = no) [boolean] Activate debugging mode. When debug is "no", all exceptions that are not caught and handled by individual tool-specific code are caught by a top-level exception handler that displays information about the exception and then exits. When debug is "yes", such exceptions are not caught by the top level code. Instead the tool produces a segmentation violation, which is more useful for debugging. When debugging mode is enabled, the tool produces more verbose output describing any errors or exceptions that are encountered. (gui = no) [boolean] Graphical user Interface (GUI) mode activated if "yes" is specified. (mode = ql) [string] Mode of automatic parameters. EXAMPLES The simplest way to run the gtpphase tool, which may suffice for most applications, is for the tool to extract the information from a master pulsar database. The exact process the tool uses for choosing ephemerides will be described below. > gtpphase evfile=fakepulsar_event.fits scfile=simscdata_1week.fits \ psrdbfile=bogus_pulsardb.fits psrname="PSR J9999+9999" ephstyle=DB Another option is to supply the essential ephemeris information manually. For example, this may be useful when an ephemeris is not available in a database, but the necessary information is available in the literature. In the example shown below, the same values which were extracted from the database in the previous example were entered manually. > gtpphase evfile=fakepulsar_event.fits scfile=simscdata_1week.fits \ psrdbfile=bogus_pulsardb.fits psrname="PSR J9999+9999" \ ephstyle=FREQ ephepoch=54870.0 timeformat=MJD timesys=TDB \ ra=111.11 dec=22.22 phi0=0.0 f0=112.345 f1=-2.345e-10 f2=3.45e-20 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 tools in Fermitools 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. Also, pulsar ephemerides for the Fermi LAT pulsars and timing models associated with various Fermi publications are available at the following web page. http://fermi.gsfc.nasa.gov/ssc/data/access/lat/ephems/ SEE ALSO gtophase, gtpulsardb