Gain Notes for Revolution 2602

N.B. The object in the FOV for this revolution was RXS J044100.3+443137 (TOO). 
This is a HMXB spectral type B0.2Ve C. It is producing a very hard signal
as background to the instrument lines and therefore we are seeing the weakest
Xe lines every seen with JEM-X, also Mo and Cu lines have been totally or
mostly swamped by this high energy signal. However, since the fitting program
can still find the Xe line this has not affected the energy calibration of
the instrument. 

This is one of the later revolutions in the mission where the calibration
sources have become so weak that for the best energy determination an
IC Gain History table is needed. These gain history tables are found
automatically by OSA, or can be downloaded from the DTU FTP site.
 
All offline gain/energy corrections (including the IC tables) are based on the
two Fe calibration sources in JEM-X1, for both units, then corrected iteratively
using the instrument background lines (Xe, backed up by Cu and Mo).

Latest OSA software (version 10 and higher) automatically cuts out the first
Science windows of data from each revolution to ensure that people do not use data
from the instrument-settling period. This process can be overruled, but only by
experienced users.
	
JEM-X1 rating: Excellent (Xe line positions within  about 2% of ideal, except for settling zone). 

JEM-X2 rating:  Very good  (within 2--3\%\ of ideal, except for settling zone, and
			a few misfitted outliers with unrealistic widths)
The JEM-X2 corrections are based on the JEM-X1 Fe calibration sources, since
all the Cd sources are now too weak to use.

CAO 09/02/2023