csphasecrv

Computes phase dependent spectra for a given source.

Synopsis

This script computes spectra by performing a maximum likelihood fit using ctlike in a series of phase bins for periodic sources. The input event list must have a PHASE column containing the phase values, that can be assigned using ctphase. The phase bins can be either specified in an ASCII file or as an interval divided into equally sized phase bins. The format of the ASCII file is one row per phase bin, each specifying the start of stop value of the phase bin, separated by a whitespace. The phase goes from 0.0 to 1.0.

csphasecrv can perform the phase curve fitting in unbinned, stacked or On/Off analysis mode; on input the script always requires unbinned data, i.e. event list(s), since only event data retain phase information for phase curve fitting. To select unbinned analysis, specify method=3D and enumbins=0; for stacked analysis specify method=3D and any positive number for enumbins. To perform the analysis in On/Off model, specify method=ONOFF.

For a stacked analysis, csphasecrv will query the parameters that define the counts cube (coordsys, proj, xref, yref, nxpix, nypix, binsz) while for an On/Off analysis the script will query the parameters that are necessary to run internally the csphagen script (inexclusion, coordsys, xref, yref, srcshape, rad, bkgmethod, bkgregmin, maxoffset, etruemin, etruemax, etruebins).

csphasecrv supports multiprocessing. By default the analysis in each phase bin will be performed in parallel over as many processes as the number of CPUs available on your machine. The maximum number of parallel processes can be set by the user through the nthreads hidden parameter.

The script writes the fit results into a FITS file. The script also produces one XML file per phase bin that contains the best-fit model for that bin.

General parameters

inobs [file]

Input event list or observation definition XML file.

inmodel [file]

Input model definition XML file.

srcname [string]

Name of the periodic source in the source model XML file.

caldb [string]

Calibration database.

irf [string]

Instrumental response function.

(inexclusion = NONE) [file]

Optional FITS file containing a WCS map that defines sky regions not to be used for background estimation (where map value != 0). If the file contains multiple extensions the user may specify which one to use. Otherwise, the extention EXCLUSION will be used if available, or else the primary extension will be used.

(edisp = no) [boolean]

Applies energy dispersion to response computation (for 3D analysis only, energy dispersion is always taken into account in ONOFF analysis).

outfile [file]

Name of the XML output file. The phase interval will be automatically appended to the name.

phbinalg <FILE|LIN> [string]

Algorithm for defining phase bins.

phbins [integer]

Number of phase bins.

phbinfile [file]

File defining the phase binning.

method <3D|ONOFF> [string]

Selects between 3D analysis (3D spatial/energy likelihood) and ONOFF analysis (1D likelihood with background from Off regions).

emin [real]

Lower energy limit of events (in TeV).

emax [real]

Upper energy limit of events (in TeV).

enumbins [integer]

Number of energy bins per phase bin (0=unbinned for 3D analysis only).

coordsys <CEL|GAL> [string]

Coordinate system (CEL - celestial, GAL - galactic).

proj <AIT|AZP|CAR|GLS|MER|MOL|SFL|SIN|STG|TAN> [string]

Projection method.

xref [real]

Right Ascension / Galactic longitude of image centre for 3D analysis or source region centre for On/Off analysis (J2000, in degrees).

yref [real]

Declination / Galactic latitude of image centre for 3D analysis or source region centre for On/Off analysis (J2000, in degrees).

nxpix [integer]

Size of the Right Ascension / Galactic longitude axis for 3D analysis (in pixels).

nypix [integer]

Size of the Declination / Galactic latitude axis for 3D analysis (in pixels).

binsz [real]

Pixel size for 3D analysis (in degrees/pixel).

srcshape <CIRCLE|RECT> [string]

Shape of the source region. CIRCLE defines a circular region around given position, RECT defines a rectangle centred on a given position.

rad [real]

Radius of source region circle for On/Off analysis (deg)

width [real]

Width of source region rectangle for On/Off analysis (deg).

height [real]

Height of source region rectangle for On/Off analysis (deg).

posang [real]

Position angle of source region rectangle for On/Off analysis, counted counterclockwise from celestial North (deg).

(bkgmethod = REFLECTED) [string]

Method for background estimation in On/Off analysis. REFLECTED: background evaluated in regions with the same shape as source region reflected w.r.t. pointing direction for each observation.

(bkgregmin = 2) [integer]

Minimum number of background regions that are required for an observation in On/Off analysis. If this number of background regions is not available the observation is skipped.

(maxoffset = 4.0) [real]

Maximum offset in degrees of source from camera center to accept the observation for On/Off analysis.

(etruemin = 0.01) [real]

Minimum true energy to evaluate instrumental response in On/Off analysis (TeV).

(etruemax = 0.01) [real]

Maximum true energy to evaluate instrumental response in On/Off analysis (TeV).

(etruebins = 30) [integer]

Number of bins per decade for true energy bins to evaluate instrumental response in On/Off analysis.

(statistic = DEFAULT) <DEFAULT|CSTAT|WSTAT|CHI2> [string]

Optimization statistic. DEFAULT uses the default statistic for all observations, which is CSTAT or the statistic specified in the observation definition XML file. CSTAT uses the C statistic for all observations, WSTAT uses the W statistic for all On/Off observations, and CHI2 uses the Chi squared statistic for all binned or stacked observations.

Standard parameters

(nthreads = 0) [integer]

Number of parallel processes (0=use all available CPUs).

(publish = no) [boolean]

Specifies whether the phase curve should be published on VO Hub.

(chatter = 2) [integer]
Verbosity of the executable:

chatter = 0: no information will be logged

chatter = 1: only errors will be logged

chatter = 2: errors and actions will be logged

chatter = 3: report about the task execution

chatter = 4: detailed report about the task execution

(clobber = yes) [boolean]

Specifies whether an existing light curve output file should be overwritten.

(debug = no) [boolean]

Enables debug mode. In debug mode the executable will dump any log file output to the console.

(mode = ql) [string]

Mode of automatic parameters (default is ql, i.e. “query and learn”).

(logfile = csphasecrv.log) [filename]

Log filename.