1. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 1 A Comparison of Spectral Fit Results of E0102 from the Chandra and XMM CCDs Paul Plucinsky & Paul Plucinsky & Joseph DePasquale Joseph DePasquale

2. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 2 Other Contributors to this Effort Other Contributors to this Effort CXC: R. Edgar, N. Schulz, A. Vikhilin MIT: K. Flanagan, D. Dewey, lots of help from MIT ACIS team

3. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 3 Why Use E0102 as a Calibration Source for the CCDs? Well-characterized spectrum, both the Chandra HETG and XMM RGS have observed the object The spectrum is relatively simple by astrophysical standards, no or very little Fe, strong lines of O, Ne, and Mg Extended source so pileup effects are minimized Constant source The O and Ne lines sample an energy range in which the on-board calibration source does not have strong lines Low-energy part of the bandpass is always a challenge to calibrate

4. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 4 Spectral Model: Calibration vs. Astrophysics Primary Objectives are to measure the gain, the spectral redistribution function, and detection efficiency in the 0.5 -2.0 keV range Our immediate concern is to develop a model useful for calibration, not to develop an astrophysically-meaningful model, We use a model consisting of 24 Gaussians for the lines identified by the HETG and RGS, a bremsstrahlung for the continuum, and a two component absorption (Galactic and SMC) Line energies are fixed at the true values and the widths of the Gaussians are fixed at zero, so the only parameter which varies is the normalization Constrain the ratio of the OVII For (561 eV)/O VII Res (574 eV) to 0.58 based on HETG and OVII (665 eV)/ OVIII Ly-alpha (654 eV) to 0.1368 (ratios from Flanagan et al. 2004)

5. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 5 ACIS-Specific Calibration Issues: CTI Correction for the FI CCDs Time-dependent gain correction for both BI and FI CCDs QE correction for the S3 CCD (summer 2004) Time-dependent and spatial-dependent correction for the contamination (aka ``The Marshall Layer’’) We used CIAO 3.2 and CALDB 3.0.0 (released Dec 2004) XMM Data: Provided by Andy Read (16 MOS1/MOS2) and Michael Smith (1 each MOS1/MOS2/PN) Chandra Data: 44 observations on I3 and 20 observations on S3, roughly once every 6 months Data (spectra, rmfs, & arfs) available at: “http:cxc.harvard.edu/acis/E0102/splash.html” Available for any one to download, please do if you would like the data !!

6. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 6 Gratuitous Pretty Pictures of E0102 S3 Summed Data ~100 ks True Color Image

7. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 7 S3(BI)

8. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 8 OVII triplet OVIII Ly-a Ne IX triplet Ne X Ly-a Mg XI triplet S3(BI)

9. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 9 OVII triplet OVIII Ly-a Ne IX triplet Ne X Ly-a Mg XI Ly-a I3(FI)

10. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 10

11. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 11

12. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 12 MOS 1 MOS 2 Thick filter Large Window

13. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 13 MOS 1 MOS 2 Thick Filter Large Window

14. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 14 PN MOS 1 MOS 2 Thick Filter Small Window

15. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 15 PN Thick Filter Small Window

16. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 16 ACIS S3 ACIS I3 MOS1/ MOS2 PN Flux(0.4-2.5 keV) (e-11 ergs cm^2 s) 2.41 [2.40,2.42] 2.52 [2.51,2.54] 2.10 [2.09,2.11] 2.49 [2.48,2.50] OVIII Ly-a (e-3 photons/ cm^2 s) 6.51 [6.14,16.9] 5.26 [4.95,5.70] 5.02 [4.93,5.16] 6.63 [6.60,7.28] Ne IX triplet (e-3 photons/ cm^2 s) 3.19 [2.58,3.80] 2.80 [2.48,3.11] 2.60 [2.51,2.69] 2.93 [2.78,3.08] Comparison of Fitted Results between XMM and Chandra

17. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 17 Mkn 421 Obsid 4148: row 178 Obsid 5332: row 512 12.35 A (1004 eV) 15.54 A ( 798 eV) 18.71 A ( 662 eV) 21.12 A ( 587 eV) 23.48 A ( 528 eV) 25.09 A ( 494 eV) Schulz (MIT)

18. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 18 Schulz (MIT) 1004 eV662 eV 587 eV 494 eV

19. Chandra X-Ray Observatory CXC Paul Plucinsky February 2005 19 Conclusions and Future Work ACIS BI and FI CCD results are more consistent than earlier, but discrepancies still exist ACIS results appear to be more consistent with the PN results We need to fit the rest of the XMM data We need to understand and constrain the relative contribution of the lines and the continuum We need to improve the BI spectral redistribution function We need to understand the apparently “discrepant” data sets for ACIS