SAS Watchout - 16.0.0 - om-grism-spectra - XMM-Newton
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:
| 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.