Ginga Specific Software: Procedure BGDUNIV.QCL
Procedure bgduniv.qcl subtracts Ginga data files
using standardised files. It should be used when no local background
is available, or for cases where the background subtraction is not
important. In addition, it can be used when comparing
"local" and "universal" background
subtraction methods for weak sources, where uncertainties due to
fluctuations in the Cosmic X-ray background are important (see Williams et al. 1992).
There are a number of sets of background coefficient files which
can be used by this procedure. Each set is derived from a few months
of off-source data. You should use the background data which is
closest to the time of your source observation. The following are
currently available:
| 87b2 |
Jun 87 |
- |
Sep 87 |
|
| 87c |
Sep 87 |
- |
Dec 87 |
|
| 88b |
May 88 |
- |
Aug 88 |
|
| 88c |
Sep 88 |
- |
Dec 88 |
|
| 89a |
Jan 89 |
- |
Apr 89 |
|
| 89b |
May 89 |
- |
Aug 89 |
|
| 89c |
Sep 89 |
- |
Nov 89 |
|
| 8912_9001 |
Dec 89 |
- |
Jan 90 |
|
| 9002_9003 |
Feb 90 |
- |
Mar 90 |
|
| 9005_9006 |
May 90 |
- |
Jun 90 |
|
| 9007_9008 |
Jul 90 |
- |
Aug 90 |
|
| 9009 |
Sep 90 |
|
|
(Detectors 5 and 6 off) |
| 9010 |
Oct 90 |
|
|
(Detectors 5 and 6 off) |
| 9011 |
Nov 90 |
|
|
(Detectors 5 and 6 off) |
| 9012_9101 |
Dec 90 |
- |
Jan 91 |
|
| 9102_9103 |
Feb 91 |
- |
Mar 91 |
|
| 9104_9105 |
Apr 91 |
- |
May 91 |
|
| 9106 |
Jun 91 |
|
|
|
| 9107 |
Jul 91 |
|
|
|
Warning: the 88c data may be affected by the problems with the
gain calibration on two of the LAC modules at this time.
Bgduniv.qcl prompts for the name of the input source CUBE
(or TIME series). This file should have been cleaned previously (using
cleanall).
Bgduniv.qcl also prompts for the names of two output files,
one to contain the model background corresponding to the period
covered by the source observation and the other to contain the
background subtracted source observation.
Bgduniv.qcl requires four input parameters. The QX parameter
system is used to read these parameters.
- The name of the input source CUBE (or TIME series).
- The name of the CUBE (or TIME series) containing the background
model corresponding to the period covered by the source
observation.
- The name of the background subtracted source observation.
- The name of the set of background coefficients to be used.
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