ctselect

Select events from event list(s).

Synopsis

This tool selects events from one or several event lists. Event selection is based on a circular acceptance region, a time interval and an energy interval. If any of these default selections are to be skipped, the user should set the relative parameters to INDEF (or NONE, UNDEF, UNDEFINED). In addition, any expression following the cfitsio syntax can be used for event selection.

The circular acceptance region is centred by default at the pointing direction of each observation, but the user can specify a custom direction. To obtain in output a valid region of interest (ROI) for subsequent analysis, the requested ROI must be enclosed in the one of the original observation.

Optionally, ctselect may also apply energy thresholds. If usethres=DEFAULT is specified, ctselect will extract any save thresholds from the instrument response functions, and if they exist, will apply them to the respective event list. Alternatively, if usethres=USER is specified, ctselect will extract any user thresholds from the observation definition file (attributes emin and emax), and if either of the attributes exists, will apply them to the respective event list.

If an event list is provided on input, ctselect creates a new FITS file on output that contains only the selected events. In case that an observation definition file is specified on input, ctselect creates for each event file referenced in the observation definition file a new FITS file with the value of prefix prepended to the file name that contains only the selected events. In addition, a new observation definition file will be written that references the new FITS files.

For each event file, the event selection parameters will be written as data selection keywords to the FITS header. These keywords are mandatory for any unbinned maximum likelihood analysis of the event data.

General parameters

inobs [file]

Input event list or observation definition XML file

outobs [file]

Output event list or observation definition XML file.

(prefix = "selected_") [string]

Prefix for output event lists in observation definition XML file.

(usepnt = yes) [boolean]

Use pointing instead of RA/DEC parameters?

ra [real]

Right Ascension of acceptance cone (or ROI) centre (J2000, in degrees). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no ROI selection will be performed.

dec [real]

Declination of acceptance cone (or ROI) centre (J2000, in degrees). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no ROI selection will be performed.

rad [real]

Radius of acceptance cone (or ROI) (in degrees). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no ROI selection will be performed.

(forcesel = no) [boolean]

Force ROI selection even if it produces invalid ROI?

tmin [time]

Start time for event selection (UTC string, JD, MJD or MET in seconds). Start times given in MET seconds are counted with respect to the time reference of the input observation(s). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no time selection will be performed.

tmax [time]

Stop time for event selection (UTC string, JD, MJD or MET in seconds). Stop times given in MET seconds are counted with respect to the time reference of the input observation(s). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no time selection will be performed.

emin [real]

Lower energy limit of events (in TeV). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no energy selection will be performed.

emax [real]

Upper energy limit of events (in TeV). If INDEF, NONE, UNDEF or UNDEFINED is passed as value, no energy selection will be performed.

(phase = NONE) [string]

String to apply a phase selection. The string must contain the boundaries of the phase interval to be selected separated be a colon. More than one interval can be specified at the same time. In this case intervals must be separated by a comma. Examples of valid strings are: phase = 0.3:0.6, phase = 0.3:0.6,0.8:0.9 or phase = 0.8:0.2. In the last case, events with phases in the intervals [0.8,1.0] and [0.0,0.2] are selected. If NONE is passed as value, no phase selection will be performed.

(expr = "") [string]

Additional event selection expression (cfitsio syntax).

(usethres = NONE) [string]

Energy threshold type (one of NONE, DEFAULT or USER).

Standard parameters

(publish = no) [boolean]

Specifies whether the event list(s) 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 existing output files 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 = ctlike.log) [string]

Name of log file.