NAME

USAGE

DESCRIPTION

Create a simulated background event file for a specific GSC camera and sky location. Events are generated for time intervals defined by an input GTI file and within a given range of energy. Events are mapped to an event file with a tangent plane centered on a sky location and distributed within a specified radius around that location. The event rate is increased by a simulation factor to ensure adequate statistical sampling.

PARAMETERS

gscid [integer]

GSC camera ID. Expected values range from 0 - 11.

gtifname [filename]

Name of the input GTI file matching the specified camera and time interval.

outfname [filename]

Output simulated background event file name.

object [string]

String value for the OBJECT keyword in the output event file.

center_ra [real] (J2000; degrees)

Right Ascension of the image center.

center_dec [real] (J2000; degrees)

Declination of the image center.

ene_lo [real] (keV)

Lower energy boundary for the simulation.

ene_hi [real] (keV)

Upper energy boundary for the simulation. Note that the simulator will not support an upper bounder higher than 20.0 keV when using the standard CALDB background template.

(radi = 8.0) [real] (degrees)

Radius of the region within which simulation events are produced. Default value is 8.0 degrees.

(nx = 200) [integer]

Number of the pixels in the x-direction of the simulated sky area. Default value is 200 pixels.

(ny = 200) [integer]

Number of the pixels in the y-direction of the simulated sky area. Default value is 200 pixels.

(pixsize = 0.1) [real] (degrees)

Pixel size. Default value is 0.1 degrees.

(sim_scale = 10) [integer]

Simulation scale factor, such that the simulated events are made at 'sim_scale' times the simulated observation data rate. A higher value provides better statistical accuracy, but takes longer to compute. The default value is 10.

(auxpath = "trend") [string]

Path to the auxiliary files. Default value is "trend".

(attlist = "iatlist.fits") [filename])

Name of the attitude file list to be used. The default is "iatlist.fits".

(vclist = "vclist.fits") [filename]

Name of the veto carbon (GSC housekeeping) file list. The default is "vclist.fits".

(allsky = no) [boolean]

Flag to generate an all-sky simulation (yes/no). Default is no.

(leapsecfile = "REFDATA") [string]

If set to "REFDATA" (default), use the built-in reference file for defining leap seconds. If set to "CALDB", use the reference file in the MAXI calibration database. Otherwise, use the specified file name.

(teldefgsc = "CALDB") [string]

The telescope definition (TELDEF) file for the specific GSC camera. The default setting of "CALDB" will obtain this information from the MAXI calibration database.

(hvhistfile = "CALDB") [file list]

The high voltage history file for the specific GSC camera. The default setting of "CALDB" will obtain this information from the MAXI calibration database.

(soyuzgti = "CALDB") [file list]

A file defining the times when a Soyuz spacecraft is docked at the ISS. Soyuz carries an radioactive source, which increases the MAXI background noise rate. The default setting of "CALDB" will obtain this information from the MAXI calibration database.

(bgtemplatefile = "CALDB") [filename]

Name of the background template file containing the camera and voltage specific settings for the cosmic X-ray background, non-X-ray background, and Soyuz-generated background used to simulate background events. If set to "CALDB" (default), the file is obtained from the MAXI calibration database.

(clobber = "yes") [boolean]

Overwrites the existing output file Default is "yes"

(history = "yes") [boolean]

Records tool parameters in HISTORY keywords if set to yes (default).

(chatter = 1) [integer]

Chatter level for output. Set to 0 to suppress output. Higher values up to 50 support increased amount of output. The default value is 1.

(mode = "ql") [string ql|hl|q]

Mode to query the parameter file. Acceptable values include: "ql" (query and learn/remember), "hl" (hidden and learn/remember), "q" (query but don't remember), "h" (hidden).

EXAMPLES

Generate a simulated event file for observations of the Crab using GSC camera 1 during scan interval defined by 'crab_g1_fov.gti'. Write the simulated events to a file 'crab_g1_bgd.evt'.
The event file projects these events into a 200 x 200 pixel tangent plane image with 0.1 degree square pixels, covering the energy range 2.0 - 20.0 keV and computed with a simulation scale factor of 10. The OBJECT keyword in the event file will be set to "Crab". Default settings include using the calibration database for high voltage history, the background contribution from non-X-ray sky background (including the presence of a docked Soyuz capsule) and cosmic background contributions, and telescope definitions. Leap second information is obtained from the built-in HEASoft reference data. The instrument orientation information is derived from the the ISS attitude files listed in 'iatlist.fits' in the directory 'trend', and the veto carbon anti-coincidence rate comes from the list of GSC housekeeping files in 'vclist.fits'.

mxsim_bgd gscid=1 gtifname=crab_g1_fov.gti outfname=crab_g1_bgd.evt \ 
    object="Crab" center_ra=83.63 center_dec=22.01 ene_lo=2.0 ene_hi=20.0 radi=8.0 \
    nx=200 ny=200 pixsize=0.1 sim_scale=10

Cavueats

This tasks is designed only for the GSC detectors. There is no background simulator for the MAXI SSC.

The values for 'nx' and 'ny' should be at least 2 x 'radi' / 'pixsize' or the simulation may be truncated by image plane sampling effects. For example, for the default settings of 'radi' = 8.0 degrees and 'pixsize' = 0.1 degrees (default sizes), 'nx' and 'ny' should be at least 160 pixels (the default for each is 200).

The CALDB background template does not support all cameras and voltages: only cameras 0, 1, 2, 3, 4, 5, 7, and 8 are supported for 1650 V settings and 1, 2, 7, and 8 for 1550 V settings: these are the most common values for the bulk of the MAXI mission. Other GSC cameras are not supported as they either ceased operation or were severly degraded early in the mission. Other voltage states are also not supported.

SEE ALSO

LAST MODIFIED