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MOS1 Timing Mode noise echo of the meteorite column Madrid, 23. March 2009. Discovery history:. During analyses of MOS1 timing mode exposures. My MOS1 timing mode spectrum of highly absorbed source 1E1740.7-2942 looks very different to MOS2/pn at low energies. - PowerPoint PPT Presentation
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XMM-Newton
1
M.Stuhlinger, ESAC
MOS1 Timing Mode
noise echo
of the meteorite column
Madrid, 23. March 2009
XMM-Newton
2
M.Stuhlinger, ESAC
Discovery history:
• During analyses of MOS1 timing mode exposures.
• My MOS1 timing mode spectrum of highly absorbed source 1E1740.7-2942 looks very different to MOS2/pn at low energies.
• Same spectrum extracted by Carlos Gabriel agrees with MOS2 and does not show low energy features.
XMM-Newton
3
M.Stuhlinger, ESAC
Different spectra extractions cause different appearance
XMM-Newton
4
M.Stuhlinger, ESAC
Discovery history:
• During analyses of MOS1 timing mode exposures.
• My MOS1 timing mode spectrum of highly absorbed source 1E1740.7-2942 looks very different to MOS2/pn at low energies.
• Same spectrum extracted by Carlos Gabriel agrees with MOS2 and does not show low energy features.
• Where do “my” low energy counts come from?Columns 320-327 show noise component shifted to lower energies with increasing RAWX.
XMM-Newton
5
M.Stuhlinger, ESAC
1E1740.7-2942
XMM-Newton
6
M.Stuhlinger, ESAC
1E1740.7-2942
RA
WX
320
RA
WX
321
RA
WX
323
RA
WX
324
RA
WX
325
RA
WX
322
XMM-Newton
7
M.Stuhlinger, ESAC
Discovery:
• During analyses of MOS1 timing mode exposures.
• My MOS1 timing mode spectrum of highly absorbed source 1E1740.7-2942 looks very different to MOS2/pn at low energies.
• Same spectrum extracted by Carlos Gabriel agrees with MOS2 and does not show low energy features.
• Where do “my” low energy the counts come from?Columns 322-325 show noise component shifted to lower energies with increasing RAWX.
• Why the difference? We both exclude the hot column RAWX=319.Carlos used RAWX [300:316] (left PSF wing only), I used RAWX [300:317] or [321:330] (both PSF
wings with gap).
XMM-Newton
8
M.Stuhlinger, ESAC
1E1740.7-2942
6 p
ixel
s to
be
ign
ore
d
XMM-Newton
9
M.Stuhlinger, ESAC
MOS1 1E1740.7-2942 (rev.1065): PI versus RAWX
RAWX 323
RAWX 322
RAWX 324
RAWX 325
RAWX 321RA
WX
319
RAWX 320
RAWX
PI
XMM-Newton
10
M.Stuhlinger, ESAC
MOS1 Swift J1753.5-0127 (rev.1152): PI versus RAWX
RAWX 323
RAWX 322
RAWX 324
RAWX 325
RAWX 321
RA
WX
319
RAWX 320
RAWX
PI
XMM-Newton
11
M.Stuhlinger, ESAC
MOS1 4U0142+61 (rev.1300): PI versus RAWX
RAWX 323
RAWX 322
RAWX 324
RAWX 325
RAWX 321
RA
WX
319
RAWX 320
RAWX
PI
XMM-Newton
12
M.Stuhlinger, ESAC
Conclusions:
• Noise echo of meteorite column in RAWX [320:325] is common feature in MOS1 timing modes.
• Most probable noise echo is created within serial readout process.
• For extraction of MOS1 timing mode spectra (Rev.>961):
Better ignore RAWX [318:325]
• Large fraction of the right (higher RAWX values) PSF wing is lost!
• Already recommended: Avoid MOS1 observations in timing mode.
