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Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April 2007 1 1.ACIS Calibration: Recent Updates, Planned Updates, & Future Issues 2.E0102: Joint.

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Presentation on theme: "Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April 2007 1 1.ACIS Calibration: Recent Updates, Planned Updates, & Future Issues 2.E0102: Joint."— Presentation transcript:

1 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April ACIS Calibration: Recent Updates, Planned Updates, & Future Issues 2.E0102: Joint Fits with ACIS S3, MOS1/2 & pn Paul Plucinsky, Joseph DePasquale, & Steve Snowden Paul Plucinsky, Joseph DePasquale, & Steve Snowden

2 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Recent Updates to the ACIS Calibration BI CCD CTI correction for -120 C (S3 & S1), need to have CIAO 3.4 also to apply the correction, BI CTI correction is now part of the standard data processing Effective area correction around the Si K edge, ~4 % at 1.8 keV FI CCD ``dead area’’ correction to account for the area lost on average in each frame to cosmic rays, % as a function of row CALDB released on 15 December 2006

3 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Planned Update: CTI Correction for Graded Mode for FI CCDs Faint mode CTI correction adjusts the PH of each pixel in the 3x3 event island In Graded mode, only have x, y position of event, grade, and summed PH Use grade and summed PH to determine the most likely charge distribution based on ``average’’ images Use this information in an Graded mode CTI correction Mn-K flight grade 8 (left split) for S2 Bottom 256 rowsTop 256 rows Vikhlinin (SAO)

4 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Map of Good and Bad Grades Vikhlinin (SAO) 33 of 256 flight grades are included in the ASCA G02346 grades Create average images for each of these 33 grades for multiple energies

5 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Comparison of Graded Mode and Faint Mode CTI Correction Posson- Brown (SAO) Graded mode CTI correction provides most of the benefit of the Faint mode correction For FI CCDs only !

6 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Continuous Clocking Mode Calibration Edgar (SAO) In CC mode: - row-to-row transfer time is different so the effects of CTI are different -- don’t know the y position of the events, but for some observations you know the y position of the source External Calibration Source: No CTI correction applied

7 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Update on Contaminant Buildup Data: Grant (MIT) Model: O’Dell & Tennant (MSFC)

8 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Optical Depth Comparison C-K Marshall (MIT) inferred optical depth at 700 eV ECS Grant (MIT) Mn L E0102 DePasquale (SAO) OVIII Ly-a

9 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Future Issues: Focal Plane Operating Temperature current operating temperature is C as the mission has progressed, the frequency and magnitude of deviations from the desired temperature have increased it might become necessary to operate at a higher temperature, significant impact for the FI CCDs

10 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April E0102: Gratuitous Pretty Pictures of E0102 S3 Summed Data ~100 ks RGS Spectrum (Pollock 2006) Objective: Objective: develop a spectral model which can be used by RGS, HETG, EPIC & ACIS, etc.

11 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Application of RGS Spectral Model Dewey (MIT) Use RGS spectral model Construct a spatial model Compare simulation to data Bright lines agree well

12 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April MEG minus 1st order Simulation Comparison KS test O VIII O VII Ne IX Ne X Mg XI

13 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April MEG plus 1st order Simulation Comparison KS test Mg XI Ne X Ne IX O VIII O VII

14 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pn SAS 7.0, latest CCF Many thanks Steve !! No fit, adopt Pollock RGS model Brems kT = 0.36 keV CCD spectra prefer a harder continuum NH=5.36e20 Line Es and widths frozen, Norms free

15 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pn Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

16 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Individual Fit with Pollock Model to ACIS S3 Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

17 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Individual Fit with Pollock Model to MOS1 Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

18 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Individual Fit with Pollock Model to MOS1: Ne lines free Fit, Brems kT =0.65 keV NH=5.36e20 Ne Line Es free, widths frozen, norms free

19 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Individual Fit with Pollock Model to pn Fit, Brems kT =0.40 keV NH=5.36e20 Line Es frozen, widths frozen, norms free

20 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Where Do We Go From Here ? Dewey analysis needs to be updated with latest response files for HRMA/ACIS/HETG Line-based analysis needs to be updated with the latest response files for HRMA/HETG/ACIS RGS data need to be re-analyzed with new background model for RGS RGS and HETG teams agree on a model well before the IACHEC meeting in California ACIS, MOS, and pn use the new model to fit the CCD spectra

21 Chandra X-Ray Observatory CXC Paul Plucinsky EPIC Cal April Let’s Agree on a Model !!!!!!! Purpose: to improve the low-energy response model of ACIS, MOS and pn CCD instruments 1)RGS and HETG agree on flux of bright lines 2)RGS and HETG compromise on existence of weak lines 3)RGS and HETG agree on widths for the lines 4)Select a continuum model and absorption 5)HETG team must analyze second epoch observations of E0102 6)Fit ACIS, MOS, and pn with the same model


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