csbkgmodel

Generates background model for 3D analysis.

Synopsis

This script generates a background model for a 3D analysis. The background model is composed of spatial and spectral components, controlled through the parameters spatial and spectral. The spatial component can be either an effective area model (AEFF), a template extracted from the instrument response function (IRF) or an analytical 2D Gaussian function (GAUSS). For the analytical 2D Gaussian function, a bilinear multiplicative background gradient can be added using gradient=yes. The spectral component can be either a power law (PLAW) or a nodes function (NODES). The number of nodes for the node function is controlled through the enumbins parameter. Specific node energies can be specified through the ebinfile parameter.

If runwise=yes, a background model component will be added for each observation in the input observation definition XML file. The script fits the background model to the input observation(s) to preset the background model parameters with reasonable values.

On output, csbkgmodel writes an model definition XML file that can be used for model fitting. Source model components have to be added as needed.

General parameters

inobs [file]

Event list, counts cube or input observation definition XML file.

caldb [string]

Calibration database.

irf [string]

Instrument response function.

outmodel [file]

Output model XML file.

instrument [string]

Instrument name for which background models should be generated. If the input observation definition XML contains only observations for a given instrument, the instrument name will be extracted from the observation definition XML file.

spatial <IRF|AEFF|LOOKUP|GAUSS|GAUSS(E)|PROFILE|POLYNOM> [string]
Spatial model component. The following options exist:

IRF: The background template included in the Instrument Response Functions will be used (energy-dependent)

AEFF: The effective area will be used (energy-dependent)

LOOKUP: A lookup table, specified by the slufile parameter, will be used (energy-dependent).

GAUSS: A radial Gaussian in offset angle squared will be used.

GAUSS(E): An energy-dependent radial Gaussian in offset angle squared will be used. The snumbins parameter specifies the number of energy nodes, the smin and smax parameters specify the energy range for the nodes.

PROFILE: A radial profile will be used.

POLYNOM: A third order polynomial will be used.

slufile [file]

Name of the file containing the lookup table if spatial=LOOKUP.

snumbins [integer]

Number of energy nodes for GAUSS(E) spatial model. This parameter is only queried if GAUSS(E) is specified as spatial model.

smin [real]

Lower energy limit of energy nodes for GAUSS(E) spatial model (TeV). This parameter is only queried if snumbins is larger than 1.

smax [real]

Upper energy limit of energy nodes for GAUSS(E) spatial model (TeV). This parameter is only queried if snumbins is larger than 1.

gradient [boolean]

Allow for a spatial gradient in the background event distribution? This option only applies to the GAUSS spatial model component.

spectral <PLAW|NODES> [string]

Spectral model component. PLAW specifies a simple power law model, NODES specifies a piecewise broken power-law.

ebinalg <FILE|LIN|LOG|POW> [string]

Algorithm for defining energy nodes. For FILE, the energy nodes are defined in a FITS file that is specified by the ebinfile parameter, for LIN and LOG there will be enumbins energy nodes spaced linearly or logarithmically between emin and emax, respectively. For POW a spacing with enumbins nodes between emin and emax will be defined so that the integral over a power law with a spectral index defined by the parameter ebingamma will be constant. A value of ebingamma=1 correspond to the LOG algorithm, a smaller value provides a finer binning for larger energies while a larger value provides a finer binning for smaller energies.

emin [real]

Lower energy limit (in TeV).

emax [real]

Upper energy limit (in TeV).

enumbins [integer]

Number of energy nodes if LIN, LOG or POW energy algorithms are used.

ebinfile [file]

Name of the file containing the energy node definition if ebinalg=FILE.

ebingamma [real]

Power law index for energy node definition if ebinalg=POW.

runwise [boolean]

Generate runwise background model? If yes is specified a background model component for each observation in the observation definition XML file will be added to the output model XML file.

(rad = 2.0) [real]

Radius for event selection. Only events within this radius around the pointing direction will be used for model fitting.

Standard parameters

(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 energy boundaries 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 = csbkgmodel.log) [filename]

Log filename.