cttsmap

Generate a Test Statistic (TS) map.

Synopsis

This tool generates a Test Statistic (TS) map for a specific source model. cttsmap works for point, radial and elliptical source models. The tool displaces the specified source on a grid of sky directions and computes for each direction the TS value for the model. The TS value is defined as twice the difference between the log-likelihood obtained for the full model (including the specified source) and the log-likelihood obtained for a model that excludes the specified source. The square-root of the TS values corresponds roughly to the pre-trial detection significance of the source (in Gaussian sigma).

cttsmap generates a FITS file comprising a sky map of TS values followed by one extension per free parameter that contains sky maps of the fitted parameter values. To save computation time, the errors are not computed by default. Specifying the hidden parameter errors=yes will switch on the error computation. Accordingly, for each free parameter, the errors are also stored in a separate sky map.

General parameters

inobs [file]

Input event list, counts cube or observation definition XML file.

inmodel [file]

Input model XML file.

srcname [string]

Name of source model for which the TS map should be computed.

expcube [file]

Input exposure cube file.

psfcube [file]

Input PSF cube file.

edispcube [file]

Input energy dispersion cube file.

bkgcube [file]

Input background cube file.

caldb [string]

Calibration database.

irf [string]

Instrumental response function.

(edisp = no) [boolean]

Applies energy dispersion to response computation.

outmap [file]

Output Test Statistic map file.

(errors = no) [boolean]

Compute and store parameter errors?

(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.

(like_accuracy = 0.005) [real]

Absolute accuracy of maximum likelihood value. Reducing this value will increase the number of iterations and provide a more accurate maximum log likelihood value. Converserly, decreasing the value will result in less iterations at the expense of a less accurate maximum likelihood value.

(max_iter = 50) [integer]

Maximum number of fit iterations.

(fix_spat = no) [boolean]

Fix spatial parameters for TS map computation.

(usepnt = no) [boolean]

Use CTA pointing direction for map centre instead of xref/yref parameters?

nxpix [integer]

Number of map pixels in Right Ascension or Galactic longitude.

nypix [integer]

Number of map pixels in Declination or Galactic latitude.

binsz [real]

Map pixel size (in degrees/pixel).

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 map centre (J2000, in degrees).

yref [real]

Declination / Galactic latitude of map centre (J2000, in degrees).

(binmin = -1) [integer]

First bin to compute.

(binmax = -1) [integer]

Last bin to compute.

(logL0 = -1) [real]

LogLikelihood value of null hypothesis.

Standard parameters

(publish = no) [boolean]

Specifies whether the TS map 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 output TS map 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 = cttsmap.log) [string]

Name of log file.