1 / 15

Calibration of the XMM-Newton RGS Andy Pollock Summary for EPIC CAL/Ops 4-5 May 2006

Calibration of the XMM-Newton RGS Andy Pollock Summary for EPIC CAL/Ops 4-5 May 2006. XMM-SOC@ESAC & SRON Utrecht. Outline. Review of ground calibration RGS stability RGS effective area Example comparisons of the newly recalibrated RGS with EPIC WHIMs. Ground calibration.

kathleen-andrews
Download Presentation

Calibration of the XMM-Newton RGS Andy Pollock Summary for EPIC CAL/Ops 4-5 May 2006

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Calibration of the XMM-Newton RGS Andy Pollock Summary for EPIC CAL/Ops 4-5 May 2006 XMM-SOC@ESAC & SRON Utrecht

  2. Outline • Review of ground calibration • RGS stability • RGS effective area • Example comparisons of the newly recalibrated RGS with EPIC • WHIMs

  3. Ground calibration  = Grating efficiency  CCD QE = effective area  RGS calibration reference band 10 ≤ λ(Ǻ)≤ 25 (6 ≤ λ(Ǻ)≤ 38)

  4. RGS stability from SNR observations OVIII Lyα NeX Lyα CVI Lyα

  5. RGS stability from SNR observations SNR 1ES0102-7219 CVI Lyα NeX(12.132Ǻ) and OVIII(18.967Ǻ) stable within a few %

  6. RGS effective area • large scales and small scales • correction strategy  EFFAREACORR* CCF for large scales • 900ks accumulated Mkn421 data  COOLPIX* CCF for small scales • this means a new CCF*

  7. RGS effective-area corrections • empirical approach • “featureless” blazar spectra show the same shape • blazars have absorbed power-law spectra (LETGS ratios  no RGS breaks) • calibrate  and normalisation with the Crab • NH(and absorption chemistry) vital

  8. RGS “rectified” fluxed spectra of two blazars These two blazars have significantly different rgsfluxer spectra but look very similar after multiplying by a powerlaw and correcting for ISM absorption. Such a plot would be flat for a properly calibrated effective area. g(λ)=λ2-αf(λ)exp(+NHσ(λ))

  9. RGS effective-area corrections • fit blazar spectrum with ISM-absorbed powerlaw 10<λ(Å)<25 • model residuals by sum of Chebyshev polynomials • repeat throughout the mission  Crab normalisation and slope adjustments • correction calculated at 5 epochs  EFFAREACORR*CCF • 8 example epochs shown here (r == XMM rev)

  10. Corrected-RGS comparison with EPIC : PKS2155-304

  11. Corrected-RGS comparison with EPIC : 3C273 RGS response to Stuhlinger et al. XCal document spectrum without adjustment

  12. Moving on to small-scales in the RGS response using 900ks of accumulated data on Mkn421…

  13. Mkn421’s accumulated 900ks RGS1

  14. Mkn421’s accumulated 900ks RGS2

  15. Mkn421’s accumulated 900ks • 85% of RGS data obey Poisson statistics • 14% exceed e-µµn/n! by <5% • 1% hot pixels or columns • 1% (new class of) cool columns  Nicastro et al.’s Mkn421 WHIMs were statistical fluctuations

More Related