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

72 APPENDIX A. BAT DATA FORMATS
A.5.2 Quadrant Rates
Quadrant rates (code “rtqd”) contain four channel light curves for each of four quadrants of the
BAT array (not background subtracted). Time binning is 1.6 seconds and what is recorded is
counts (not counts/second). The four channels correspond to the four nominal energy bands used
in the trigger task. (15-25, 25-50, 50-100,100-350 keV). Events with energies < 15 keV or > 350
keV are not included in these rates. The four quadrants are Blocks 0-3, 4-7, 8-11 and 12-15. These
rates do not appear if the data ingest task is not running.
Name Format [Units] Comment
TIME 1D [s] TIME of Rates
QUAD0 COUNTS 4I [count] Quadrant 0 counts per 1600 ms time bin in 4 energy bins
QUAD1 COUNTS 4I [count] Quadrant 1 counts per 1600 ms time bin in 4 energy bins
QUAD2 COUNTS 4I [count] Quadrant 2 counts per 1600 ms time bin in 4 energy bins
QUAD3 COUNTS 4I [count] Quadrant 3 counts per 1600 ms time bin in 4 energy bins
A.5.3 64-Millisecond Rates
64-msec rates (code “rtms”) contain a single four channel light curve giving the counts in the entire
array with 64-msec time binning (not background subtracted). The energy ranges are the same as
for the quadrant rates. What is reported is counts (not counts/second).
Name Format [Units] Comment
TIME 1D [s] TIME of Rates
COUNTS 1J [count] Array counts per 1 s bin in 4 energy bins
A.5.4 Maximum Rates
Max rates (code “rtmc”) represent the maximum rates detected by the BAT over multiple time
scales (not background subtracted). During each 8 second interval, the flight software checks
each 4 ms, 8 ms, 16 ms, 32 ms and 64 ms time bin, in four energy bands, and using multiple
spatial selections. There are five HDU extensions, corresponding to the five time bin sizes. Each
extension contains nine four-channel series, sampled every eight second. The nine light curves in
each extension correspond to the full array, the four quadrants (described under quadrant rates
above) and four halves. The halves correspond to all possible adjacent pairs of quadrants, namely
quadrants 0 &1, quadrants 0 & 2, quadrants 1 & 3, and quadrants 2 & 3. The five light curve
extensions are MAX COUNTS DTMS, where DT is one of (04, 08, 16, 32 or 64).
The light curves contain, for each eight second time bin, the maximum counts on the given time
scale within those eight seconds. For example, regard the MAX COUNTS 04MS extension. There
are 2000 4-ms intervals within eight seconds. What is reported in the file is the number of counts
in the 4-ms interval with the highest number of counts (in other words, the peak of the 2000 bin
light curve). The same algorithm is used for the other four time scales.
This light curve is used for on-board triggering of short bursts. On the ground, it is mostly
used for diagnostics.
Layout. Max counts for the XX millisecond time bins. EXTNAME = ‘MAX COUNTS XXMS’’