The Reflection Grating Spectrometer The Reflection Grating Spectrometer

on board of XMMon board of XMM--NewtonNewton

J.W. den HerderJ.W. den Herder

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contentscontents

•• InstrumentInstrument

•• Major operational eventsMajor operational events

•• Science impactScience impact

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InstrumentInstrument

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RGS Focal

plane Camera

Reflection

Grating Array

Analog electronics

Digital electronics

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2x2x

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Major Operational eventsMajor Operational events

•• The first power The first power •• The first XThe first X--raysrays•• The first spectraThe first spectra•• The first problemThe first problem•• The second problemThe second problem•• Cooling downCooling down•• The third problemThe third problem

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Power to the Power to the instrument: instrument: 4 4 janjan 20002000

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Opening of the detector door: Opening of the detector door: 25 25 janjan 200020006 6 febfeb 20002000

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The first data: HR1099, revolution 24The first data: HR1099, revolution 24

Data and spectraData and spectra•• Resolution as predictedResolution as predicted•• Position slightly offPosition slightly off•• Tuning of detector Tuning of detector

correction factors to be correction factors to be donedone

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The first problemThe first problem

•• Failure of standard Failure of standard HI303 analogue HI303 analogue switch in RGS2 CCD4 switch in RGS2 CCD4 on 30 January: loss on 30 January: loss of one channel (out of of one channel (out of 18)18)

16 V

- 16 V

Serial clock

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The second problemThe second problem

•• 2 Sept 2000: failure of 2 Sept 2000: failure of second chain: current second chain: current limits +16 and limits +16 and --16V 16V exceededexceeded

•• Detailed analysis: either Detailed analysis: either analogue switch or short analogue switch or short in CCD (metallic particle in CCD (metallic particle on interconnections)on interconnections)

•• Lowered operational Lowered operational voltages to reduce voltages to reduce load/stress on load/stress on componentscomponents

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Curing radiation damage: cooling from Curing radiation damage: cooling from --80 to 80 to --110110ooCC

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Current limiterCurrent limiter

•• Error flag appeared occasionally in Error flag appeared occasionally in the data stream but data was ok the data stream but data was ok (13 (13 febfeb 2004)2004)

•• Due to too narrow bounds in current Due to too narrow bounds in current limiter (aging and temperature limiter (aging and temperature dependent)dependent)

•• Readout through single node with Readout through single node with virtually no loss of science (17 Aug virtually no loss of science (17 Aug 2007)2007)

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contaminationcontamination

•• RGS is cooled to RGS is cooled to --110110ooC and open C and open to telescope tube: to telescope tube: cryocryo pumppump

•• Slow accumulation of hydroSlow accumulation of hydro--carbons (as expected)carbons (as expected)

•• Potential to decontaminate (heat Potential to decontaminate (heat up) but not done: risk cannot be up) but not done: risk cannot be quantified, hydroquantified, hydro--carbons may carbons may stick after large UV dosestick after large UV dose

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Science impact: cooling flows in clusters of galaxiesScience impact: cooling flows in clusters of galaxies

PrePre--XMMXMM•• gas in center of clusters of gas in center of clusters of

galaxies cools by collision of galaxies cools by collision of hot particles emitting Xhot particles emitting X--rays and subsequent rays and subsequent contraction: cooling flowcontraction: cooling flow

•• Not consistent with RGS Not consistent with RGS datadata

Current knowledgeCurrent knowledge•• black holes heat the center black holes heat the center

by blow of enormous by blow of enormous bubblesbubbles

Peterson et al.

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Active Galactic Nuclei: NGC 1068 (Seyfert 2 AGN)

•• Broadened (300Broadened (300--700 km/s) and 700 km/s) and shifted (shifted (blueshiftsblueshifts of 0 of 0 –– 600 km/s)600 km/s)

•• RadiativeRadiative Recombination Continua: Recombination Continua: kTkTee ~ few ~ few eVeV: photo ionized: photo ionized

•• Pure photo ionized spectrum gives Pure photo ionized spectrum gives no correct description of the data (R no correct description of the data (R ~ 3): photo excitation needed~ 3): photo excitation needed

Kinkwabhala

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Full wavelength coverageFull wavelength coverage

88% of instrument area: since 88% of instrument area: since septsept 20002000

one redundant chain in RGS2: cause well understoodone redundant chain in RGS2: cause well understood

radiation damage: <3 % after 20 yearsradiation damage: <3 % after 20 years

contamination: gradual increase hydrocarbons over mission life tcontamination: gradual increase hydrocarbons over mission life time:ime:maximum effect at 30maximum effect at 30ÅÅ (75% transmission) (75% transmission) which will decrease to 60% after 20 years which will decrease to 60% after 20 years