Update on ACIS Calibration

Chandra X-Ray Observatory CXC

Paul Plucinsky EPIC Cal 20101

Update on ACIS CalibrationUpdate on ACIS Calibration

1) Update to the ACIS contamination model2) Temperature-dependent CTI correction for FI and BI CCDs3) Cross-calibration with G21.5-0.9



Why Update the ACIS Calibration Model ?Why Update the ACIS Calibration Model ?

The growth of the contaminant with time has been diverging from the model

Optical depth at 660eV (Vikhlinin SAO) Optical depth at C-K (Marshall MIT)



E0102 Flux vs. Time with Previous Contaminant ModelE0102 Flux vs. Time with Previous Contaminant Model

DePasquale (SAO)

Blue (full frame)

Red (subarray)



E0102 Flux vs. Time with New Contaminant ModelE0102 Flux vs. Time with New Contaminant Model

DePasquale (SAO)

Blue (full frame)

Red (subarray)



E0102 OVIII Flux vs. Time with Previous Contaminant ModelE0102 OVIII Flux vs. Time with Previous Contaminant Model

DePasquale (SAO)

Blue (full frame)

Red (subarray)



E0102 Flux vs. Time with New Contaminant ModelE0102 Flux vs. Time with New Contaminant Model

DePasquale (SAO)

Blue (full frame)

Red (subarray)



Change in Effective AreaChange in Effective Area

DePasquale (SAO)



Comparison to MOS and pn and other instrumentsComparison to MOS and pn and other instrumentsOVII black OVIII red NeIX green NeX blue DePasquale(SAO))



Temperature-Dependent CTI CorrectionTemperature-Dependent CTI Correction• many observations were affected by a warm FP temperature before April 2008• FI and BI CCDs have different T dependence of CTI, FI CTI gets worse with increasing T, BI CTI gets slightly better• simply scaling the CTI correction with temperature recovers the mean PH well but the FWHM is significantly larger

Grant (MIT)



Temperature-Dependent CTI CorrectionTemperature-Dependent CTI Correction Grant (MIT)



Temperature-Dependent CTI Correction for I3Temperature-Dependent CTI Correction for I3 Posson-Brown (SAO)



Temperature-Dependent CTI Correction for S3Temperature-Dependent CTI Correction for S3 Posson-Brown (SAO)



Temperature-Dependent CTI CorrectionTemperature-Dependent CTI Correction Posson-Brown (SAO)



Cross-Calibration with G21.5-0.9Cross-Calibration with G21.5-0.9 Posson-Brown (SAO)

• much simpler spectrum than E0102, but extraction region is an issue• flux measurements in the 2.0-8.0 keV bandpass should be consistent with the cluster analysis



G21.5-0.9 Spectral Fit Results and 1G21.5-0.9 Spectral Fit Results and 1 CLs CLs

Instrument NH(1022 cm2) Index Flux(10-11) (2-8 keV) ergs cm-2 s-1

Red Chi

DOF

MOS1 2.90[2.87,2.94] 1.80[1.79,1.82] 5.46[5.43,5.49] 1.11 276

MOS2 2.91[2.88,2.95] 1.85[1.83,1.87] 5.28[5.26,5.31] 1.07 274

pn 2.76[2.74,2.79] 1.79[1.78,1.80] 5.61[5.59,5.63] 1.10 655

ACIS S3 3.07[3.05,3.09] 1.84[1.83,1.85] 6.06[6.04,6.08] 0.99 2281

Suzaku 3.20[3.18-3.22] 1.91[1.90-1.92] 6.38[6.36-6.41] 1.03 1733

Swift 0+1 2.93[2.87-2.99] 1.77[1.75-1.80] 5.61[5.56-5.65] 1.02 903

Swift 1+2 3.10[3.05-3.16] 1.91[1.89-1.94] 5.46[5.41-5.50] 1.11 969

• Preliminary results from non-thermal SNR IACHEC working group•The 2-8 keV flux should be consistent with what has been found in the cluster analysis, namely ACIS is the highest, MOS1/2 are 5% lower than ACIS and pn is 5% lower than MOS• we need to explore why this might be different than the cluster analysis, we should fit MOS, pn, and ACIS with the same NH and power-law index and then compare fluxes

Tsujimoto et al.



Backup MaterialBackup Material



IACHEC Thermal SNR Working GroupIACHEC Thermal SNR Working Group

XMM-Newton RGS Andy Pollock (ESAC)

Chandra HETG Dan Dewey (MIT)

XMM-Newton MOS Steve Sembay (Leicester)

XMM-Newton pn Frank Haberl, Victoria Grinberg (MPE)

Chandra ACIS Joe DePasquale, Paul Plucinsky (SAO)

Suzaku XIS Eric Miller (MIT)

Swift XRT Andrew Beardmore, Olivier Godet (Leicester)

Models Randall Smith (SAO/GSFC)

One of the “Standard candle” working groups.:One of the “Standard candle” working groups.:

Plucinsky et al., 2008 SPIE, Vol. 7011, arXiv:0807.2176



Chandra Images of E0102: Chandra Images of E0102: S3 Summed Data ~248 ksS3 Summed Data ~248 ks

Three Color ImageThree Color ImageRed: 0.2-0.75 keV, Green: 0.8-1.1 keV, Blue: 1.1-2.0 keV

o Young (~1,000-2,000 yr) SNR in the SMC (D~61 kpc), classified as “O-rich” SNR

o Relatively simple morphology, but significant spectral variations

DePasquale (SAO)

45 arcseconds

1E 0102.2-7219 1E 0102.2-7219



XMM-Newton RGS Spectrum of E0102:XMM-Newton RGS Spectrum of E0102:

Spectrum dominated by O & Ne,

little or no Fe emission

OVIII

OVII

CVIOVIII

NeIX

NeX

Haberl Grinberg (MPE)



OVII black OVIII red NeIX green NeX blueComparison of OVII, OVIII, NeIX, & NeX Normalizations:Comparison of OVII, OVIII, NeIX, & NeX Normalizations:

• 28 of 32 normalizations agree to within +/- 10%

• appears to be a 4% difference between RGS1 & RGS2 which is mostly independent of energy

• uncertainties are the statistical uncertainties and underestimate the true uncertainty

• MOS QE was adjusted in 2007 with the intent of improving agreement with the RGS

• ACIS, XIS, & XRT show similar trend with energy

• max differences are 23% at O VII, 24% at O VIII, 13% at Ne IX, and 19% at Ne X

• RGS, HETG, ACIS, MOS, XIS0 agree to within +/- 5% at Ne IX and Ne X

DePasquale(SAO))



Census of ACIS Modes and CTI Correction Census of ACIS Modes and CTI Correction

Mode Corrections/Calibrations % & number of Observations

TE Faint CTI correction for all 10 CCDs 46.4% (3205)

TE Very Faint

CTI correction for all 10 CCDs 48.9% (3377)

TE Graded

Prototype CTI correction for 8 FI CCDs

BI CCDs use spatial gain correction

1.4% (94)

CC Faint Prototype CTI correction for 10 CCDs 2.2% (153)

CC Graded

?? Hybrid approach of Vikhlinin graded mode correction and Edgar CC CTI ??

1.1% (73)

Clocking Modes: “Timed Exposure” (TE) and “Continuous Clocking (CC)Telemetry Formats: “Faint” (F) reports 9 PHs in 3X3 event island “Very Faint” (VF) reports 25 PHs in 5X5 event island “Graded” (G) reports a summed PH all modes report frame #, position, grade, & summed PH

Update on ACIS Calibration

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