The SWIFT BAT Software Guide Version 6.3 30 ... - HEASARC - Nasa

182 APPENDIX D. BAT SOFTWARE TOOL REFERENCE
by examining the mean sample rate. A value of 0.0 indicates the global bayesian block
optimization should be performed.
(timedel = 100e-6) [real ]
Internal time quantization size. Time resolutions more finely sampled than timedel are lost.
(ncp prior = 6.0) [real ]
Log parameter prior for the number of “change points” between Bayesian blocks. This parameter
acts as a smoothing parameter which weights against separate blocks. A smaller
number permits less significant changes to be “detected,” while a larger number requires
more significant changes to be “detected.”
(bkgsub = NO) [boolean ]
Automatic background subtraction, for computation of duration measures and fluence estimates.
(coalescefrac = 0.05) [real ]
The background subtraction and T50/T90 algorithms depend on the first and last Bayesian
blocks being representative of the true local background. If there is an outlier block, this may
heavily skew the background and duration calculations. If this parameter is non-zero, and
if the first or last block has a shorter duration than (coalescefrac)×(its neighbor’s duration),
then the two blocks are coalesced into one. Note that this will erroneously ignore real variations
if they fall at the extremes of the time series. Also, the coalescence is not iterative; the
check is done only once.
(timecol = “TIME”) [string ]
Name of the light curve time column.
(countscol = “INDEF”) [string ]
Name of the light curve rate or counts column. For a value of INDEF, battblocks will search
for RATE and COUNTS columns, in that order.
(errcol = “ERROR”) [string ]
Name of the light curve gaussian error column. Not used for event or Poisson light curves.
(expocol = “INDEF”) [string ]
Name of the light curve per-bin exposure column. For a value of INDEF, battblocks searches
for the TIMEDEL and EXPOSURE columns, in that order. If expocol/TIMEDEL/EXPOSURE
is not found, then the file is searched for a TIMEDEL or EXPOSURE keyword.
(hduclas3 = “INDEF”) [string ]
Default value of the HDUCLAS3 keyword, if one is not present in the file. If both hduclas3
and countscol are “INDEF”, then battblocks will search for a RATE or COUNTS column
and set hduclas3 according to which column is found.
(diagfile = NONE) [string ]
Diagnostic output file, used for internal debugging purposes. NONE indicates no diagnostic
output should be made.
(clobber = NO) [boolean ]
If the output file already exists, then setting “clobber = yes” will cause it to be overwritten.