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Temporal and spatial variability of the MOS RMF. Introduction and brief history of the rmf problem Investigation of the spectral evolution of Zeta Puppis as seen by the MOS CCDs, comparing the spectra in the core of the psf with that seen in the wings…i.e. a temporal and crude spatial analysis. - PowerPoint PPT Presentation
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XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Temporal and spatial variability of the MOS RMF
1. Introduction and brief history of the rmf problem
2. Investigation of the spectral evolution of Zeta Puppis as seen by the MOS CCDs, comparing the spectra in the core of the psf with that seen in the wings…i.e. a temporal and crude spatial analysis.
3. Investigation of the observed relative fluxes in 15 on-axis point sources (AGN) as measured in MOS1 and 2, pn and RGS1+2.
4. A new RMF for the MOS and its implications in terms of
spectral fitting.
5. Andy will then present a detailed analysis of temporal and spatial variability in the rmf as revealed by mapping of the SNR 1ES0102
6. Implications for the user !!!
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
E1+E2
Measurements from the Orsay
Synchrotron of MOS1/CCD1
The low energy redistribution
function of the MOS CCDs
has a complex shape.
The main photopeak has a
secondary component (shoulder)
which relatively increases with
descreasing energy until it is the
dominant component.
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Surface electrode structure
of a type 22 EEV MOS
CCD.
The etched areas of
the open phase in a single
pixel are marked in red.
Difference in redistribution
shape of mono and
bi-pixels indicate charge
loss shoulder in mono
pixels is much stronger
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Surface electrode structure
of a type 22 EEV MOS
CCD.
Difference in redistribution
shape of mono and
bi-pixels indicate charge
loss shoulder in mono
pixels is much stronger
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Effect most pronounced at lower
energies
Shift in spectrum to lower energies
Intrinsic change in redistribution
properties of the central CCDs:
Open filter observations of
the INS RX J0720
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Significant change at low energies
Evolution of the redistribution function in current SAS
Smaller change at higher energies:
Integrated photopeak at 550 eV
down by ~ 4%
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Zeta Puppis:
Early O-type Supergiant
Distance 429 pc, mv=2.25
Observation from Rev 156
Useful for checking CCD rmf
especially around ~400-450 eV
due to strong N lines
Poor fit in wings of rmf due
limitations of mathematical model
and intrinsic spectral uncertainties
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Five Observations of Zeta Puppis analysed to date:
•On Axis: Rev 156, 542, 636 and 795
•Off Axis: Rev 903 (RGS Test)
All Large Window and Thick Filter in both MOS Cameras
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
156156 542
636 903
Here are four off them…….. MOS1
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
ON-AXIS 542,636,795
ON-AXIS 156
OFF-AXIS 903
MOS1
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Spectral fitting with current epoch-dependant rmf
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
100-300 eV 350-650 eV
Investigate epoch and spatial dependant variations in the core and wings
spectra in 3 Energy bands
100-650 eV
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Rate down 8%
Flux down 5%
Eff. Area down 3%
Count Rate/Effective Area normalised to Rev 156 DatumComparison of high energy portion of the spectra from 795 and 903
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Comparison study (MOS v pn v RGS) of 15 on-axis point sources:all AGN, all similar soft/excess or steep spectrum with columns ~few 1020 cm-2
Revolution Target MOS1 MOS2 pn
94 3c 273 sw/med sw/med sw/med
96 3c 273 sw/med sw/med sw/med
161 Mkn 509 sw/thin sw/thin sw/thin
186 Ton S 180 tu/med sw/med sw/med
250 Mkn 509 sw/thin sw/thin sw/thin
277 3c 273 sw/med sw/med sw/med
450 PKS 2155-304 sw/med sw/med sw/med
468 Ton S 180 tu/med sw/med sw/med
563 3c 273 sw/med sw/med sw/med
655 3c 273 sw/thin sw/thin sw/thin
680 3c 120 tu/med sw/med sw/med
835 3c 273 sw/thin sw/med sw/thin
835 3c 273 sw/med sw/med sw/med
853 H1426+428 sw/med sw/thin sw/med
885 3c 390.3 sw/med sw/med sw/med
Methodology:
1) Use a conservative 15-40 arcsec
radius extraction annulus for all
EPIC targets to minimise pile-up.
2) Calculate fluxes in selected
energy bands using an absorbed
power-law model.
3) Compare flux ratios as function
of epoch.
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Drop in area under main
Photopeak at 550 eV = 4%
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
Consequence for continuum fitting…..I
Flux 0.4-0.8 keV
x10-11 ergs cm-2s-1
pn (new): 1.02 (0.05)
M1 (new): 0.90 (0.10)
M1 (old): 0.86 (0.10)
XMMEPICMOS
Steve Sembay ([email protected])Mallorca 02/02/05
1. Change the boresight….ok for point sources but
doesn’t help extended sources.
2. Define set of fixed rmfs for particular spatial regions
and average the rmfs for a given extraction region.
3. Come up with a correction scheme on a per-pixel (or
event basis) so that the spatial (and temporal)
dependancy is accounted for at the event processing
level.
Possibilities…..
