hxtlcurv HEADAS help file

NAME

hxtlcurv - produce background-corrected RXTE HEXTE light curves

USAGE

          hxtlcurv [-i "hexte science data file name"]
                   [-k "hexte dead-time coefficients file name"]
                   [-r "hexte 16-s hk file name (contains Rates)"]
                   [-b "bin size in seconds"]
                   [-g "good-time-interval file name"]
                   [-t "timeint file name, produced by timetrans"]
                   [-l "lower energy channel number for light curve"]
                   [-u "upper energy channel number for light curve"]
                   [-d "data column list (archive files only)"]
                   [-e "detector list for dead time correction"]
                   [-c "chatter level for hxtdead"]
                   [-p "make pha files too"]
                   [-v (version number written to standard output)]
                   [-h (help text written to standard output)]

DESCRIPTION

hxtlcurv produces a background subtracted light curve and optionally an average spectrum from HEXTE science or archive data using the off-source rocking measurements. Standard interval selection options are supported. In addition to the data file, required inputs include the contemporaneous HEXTE rates file and deadtime coefficients files. The hxtlcurv script queries the user for each of these as needed. If no timeint file is given, the TSTART and TSTOP keyword values from the science file are used. The script then checks for source and background files having the same name as the sci- ence file with the addition of "_src" or "_bkg" suffixes, respectively. If these are not found, hxtback is run to produce them. Then either saextrct or seextrct is run to produce the light curve files, which are passed to hxtdead for deadtime correction. Finally, a background light curve is interpolated and passed to lcmath for background subtrac- tion from the source-looking light curve.

PARAMETERS (SWITCHES/FLAGS)

-i infile

The name of the input HEXTE science FITS file that is to be operated upon. Output files will also start with this name.

-k hexte 128-s housekeeping file name

The name of the 128-s housekeeping file associated with the science data. This file is needed by hxtdead.

-r hexte 16-s hk file name

The name of the 16-s housekeeping file associated with the science data. This file contains rates and is needed by hxtdead.

-b tbin

time bin size for output light curve. Must be 16 seconds or less. Default is 16 seconds.

-d (archive data)

archive data column names. Must be either TimSerCnt or some combination of SpecDet0 SpecDet1 Specdet2 Specdet3. Default is all 4 spectral columns.

-e (number)

detectors subset for which dead-time correction is done by hxtdead. Default is 0123 (all of them).

-t timeint file name

Name of file containing start and stop times, produced by timetrans.

-l lower energy channel

The low energy channel number for the light curve.

-u upper energy channel

The upper energy channel number for the light curve.

-c chatter level

The chatter level for hxtdead.

-p

pha files will also be accumulated and deadtime corrected

-v

hxtlcurv version information will be written to standard output.

-h: This help text will be written to standard output.

EXAMPLES

1. hxtlcurv -h: Help text will be displayed.
2. hxtlcurv: User will be prompted for filenames. Default time bins of 16 sec.
3. hxtlcurv -i FS50_3f3ad0b-3f3b040 -r FH53_3f3ad0b-3f3b040 -k caldb -b 4.0 -g good.gti: Script will run without prompting, using FS50_3f3ad0b- 3f3b040 as science input file, FH53_3f3ad0b-3f3b040 as rates file, and the deadtime coefficients file which has been installed in the calibration database. Four second time bins. GTI file good.gti is ANDed with rocking GTIs.
4. hxtlcurv -i FS52_3f3ad0b-3f3b040 -r FH53_3f3ad0b-3f3b040 -k caldb -b 4.0: Script will run without prompting, using FS52_3f3ad0b- 3f3b040 as archive input file, FH53_3f3ad0b-3f3b040 as rates file, and the deadtime coefficients file which has been installed in the calibration database. Specified four second time bins will be changed to 16 sec by the extract tool.
5. hxtlcurv -i FS52_3f3ad0b-3f3b040 -r FH53_3f3ad0b-3f3b040 -k caldb -b 2 -d TimSerCnt: Runs as above, producing two second rate averages of the 1-second archive multiscalar data.

CAUTIONS

Limited by the rocking and the extract tools to time bins of 16 seconds or less, and 16 seconds only for archive spectral data. Calculated errors assume incorrectly that background estimates are independent, not quite true. The RMS is under- estimated by 20 percent in the worst case of weak source and 16-sec time bins. Some point-to-point correlation up to 32 seconds is also present. Rocking data only. No list-of-files option for input.

BUGS

The script has not been made operational under VMS. Channel selection with archive multiscalar data produces zero rates. This appears to be a bug in saextrct. Use event-list data if you want a light curve with time bins shorter than 16 sec and a limited channel range.

Please report problems to xtehelp@athena.gsfc.nasa.gov.