SAS Watchout

How can I correct OM Grism Spectra for Time Sensitivity Degradation?

Correction factors for OM grism spectra have been derived by measuring the variations in the white dwarfs standard stars observations and are given in the following table:

Correction factor for time dependent sensitivity degradation of the OM grisms
 
Year UV_Grism V_Grism
2000 1.00 1.00
2002 1.011 1.009
2004 1.023 1.018
2006 1.035 1.027
2008 1.047 1.036
2010 1.060 1.046
2012 1.073 1.055
2014 1.086 1.065
2016 1.100 1.075
2018 1.114 1.085
2020 1.128 1.096
2022 1.142 1.106
2024 1.157 1.017

 

After processing the OM Grism data with SAS (using omfchain) the extracted spectra are contained in the *SPECTR*.FIT files. These files contain the measured rates and the calibrated flux. These are to be multiplied by the corresponding time dependent factor given in the table.