MOS Timing Mode calibration Marcus G F Kirsch
MOS Timing Mode calibration Marcus G. F. Kirsch, B. Altieri, R. Saxton XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 1
menu EPIC · energy calibration · flux calibration · MOS Timing versus pn XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 2
Situation last cal meeting · Timing mode is overcorrected by up to 1. 5 % EPIC · · black: LW red: Timing · trend is similar for both MOSs XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 3
reason for over correction EPIC · CTI correction is performed for events with y-values from 0 -1024 (just a counter with no meaning in that mode) with the mean of ~ 500 · CTI correction should however be performed for y=300 for ALL events Now implemented in SAS 6. 0 XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 4
1 E 0102 -SAS 6. 0 EPIC · 0. 4 -2. 0 ke. V: Timing mode agrees with LW mode within +/- 0. 5 %. XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 5
SS 433: SAS 6. 0 · · pn(Timing) > MOS ? pn(Timing) = pn(FF)± 0. 3 % at 6 ke. V ~ +0. 3 % EPIC M 1 Timing Medium M 2 FF Medium pn SW Medium XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 6
Cas-A analysis 2002 EPIC · pn < Chandra < MOS · Rational: – CAS-A is very bright – MOS CTI model does not take precursors into account CTI over correction · contradictory to SS 433 ? ? ? XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 7
Flux: Calibration source EPIC · MOS 1 flux in Timing mode at Mn seems to be 10 % lower XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 8
Flux: NGC 5548 (rev 290) EPIC MOS Timing Medium M 2 SW Medium pn SW Medium · Fit: const*(model_linked) –M 1: 1. 0 –M 2: 1. 02 –PN: 1. 16 · below 0. 6 ke. V: – MOSs agree – but less flux than pn · above 8 ke. V problem in MOS Timing mode XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 9
Flux: SS 433 (rev 610) pn Timing Medium M 1 Timing Medium M 2 FF Medium EPIC · Fit const*(model_linked) –pn: 1. 0 –M 1: 0. 94 –M 2: 0. 52 (pileup) · below 0. 6 ke. V: problem in MOS Timing mode · above 8 ke. V problem in MOS Timing mode XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 10
Flux: HER-X 1 (rev 207) Fit with linked parameters and const pn Timing MOS 1 Timing · pn: 1 · MOS: 0. 9 EPIC Fit with free parameters and const=1 pn Timing MOS 1 Timing · flux in 0. 315 - 10. 0 ke. V – pn: 1. 66 E-09 erg cm-2 s-1 – MOS: 1. 55 E-09 erg cm-2 s-1 – MOS/pn: 0. 93 XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 11
Summary EPIC Energy calibration: · MOS timing mode energy calibration agrees within ± 0. 3 % with MOS-LW data · at ~ 6 -7 ke. V – pn Timing mode > MOS Timing mode by 0. 3 % (SS 433) – pn Timing mode > pn FF mode by 0. 3 % (Cas-A) – MOS FF mode should agree there with MOS Timing mode if source is not extended and bright · · For bright extended sources MOS would need a rate dependent CTI model ! Rev 832: Cas-A observation in – pn: FF and ext. FF – MOS: Timing and LW Cas-A data for all EPIC modes + other SNR data will allow overall energy calibration analysis Flux calibration: · Discrepancy of up to 10 -15 % at energies below 1 ke. V · Contradictory results for different targets and observations Is the MOS timing mode not stable in flux ? XMM-Newton Marcus Kirsch Science Operations & Data Systems Division Research & Scientific Support Department Page 12
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