Characteristics of the L7- 240 model:
Excess variance: < 0.1 ct/sec (2 -10 keV)
Excess variance: < 0.1 ct/sec (10-20 keV)
Reliable spectral subtraction for energies where net signal is > 0.01 ct/sec/keV
Applicability:
High voltage epoch 3 ( April 14, 1996 - present)
PCU 0,1,2
PCU 3,4 to be added with June 26, 1998 ftools patch
suitable for source with < 100 ct/sec
available from xtehelp@athena pending release of patch
Examples:
MCG 2-58-22 is an ~ 1 mCrab source (2-10 keV count rate = 10 ct/sec/3 PCU).
Data and background model for MCG 2-58-22
Data minus background model for MCG 2-58-22
Blank sky: ~ 2 days from a recent nearly continuous observation
Rates showing Raw rate, background model, and net rate
Power Spectrum using the Lomb algorithm from Press et al.; note
that there is some residual power at daily (frequency ~ 10e-5) and orbital (frequency ~
1.7e-4) time scales.
USAGE NOTES: (added 8-28-98)
Use the L7/240 background models for data with
Source counting rate < 40 ct/s/PCU,
and make .gti files by using MAKETIME on your XTE filter file
with the following selection expressions:
time_since_saa .gt. 30.0 .or. time_since_saa .lt. 0.0
electron0 .lt. 0.1
elv .gt. 10.0
These filter files may be entered in your SAEXTRCT runs by
writing their names to an ASCII file (e.g. 'gti.files') and
entering "@gtifilenames" at the GTIANDFILE prompt. See the GOF
recipes or contact
xtehelp@athena if the meaning of these selections is not clear.