1. EVALUATION OF THE XMM NEWTON CROSS CALIBRATION ARCHIVE
Ana García Ruiz de Gopegui
ESAC trainee Oct-Dec 2009
Supervisor: Martin Stuhlinger

2. Evaluation of the XMM Newton Cross Calibration Archieve
INDEX
1. PURPOSE
2. INTRODUCTION
3. PSF
4. PILE-UP
5. OVERVIEW OF THE SCRIPT
6. RESULTS
7. SUMMARY
8. OUTLOOK
Evaluation of the XMM Newton Cross Calibration Archieve

3. Evaluation of the XMM Newton Cross Calibration Archieve
1. PURPOSE
Create a tool to verify that the results of spectral analysis do not depend on the extraction region.
The goal of this tool:
-easy to use
-automatic
-generic
-fast
-useful for all type of point source
Evaluation of the XMM Newton Cross Calibration Archieve

4. Evaluation of the XMM Newton Cross Calibration Archieve
2. INTRODUCTION
XMM-Newton: Most powerful X-ray telescope launched in December, 1999.
Carries 3 different types of instruments:
EPIC (European Photon Imaging Camera)‏
3 CCD cameras for X-ray imaging and moderate resolution spectroscopy
2 different types of EPIC cameras: MOS and PN
RGS (Reflecting Grating Spectrometer)‏
High-resolution X-ray spectroscopy
Optical Monitor (OM)‏
For optical/UV imaging and grism spectroscopy.
Evaluation of the XMM Newton Cross Calibration Archieve

5. 3. Point Spread Function (PSF)‏
Determine the ability of an X-ray mirror to focus photons.
PSF differs slightly between telescopes.
The PSF can be affected by pile-up effects when the count rate exceeds certain limits of counts per frame.
(a) 3D PSF without pile-up
(b) 3D Pile-up PSF
Evaluation of the XMM Newton Cross Calibration Archieve

6. Point Spread function for MOS1
(heavily piled-up to show the substructures)
Front view of the mirror
Evaluation of the XMM Newton Cross Calibration Archieve

7. Evaluation of the XMM Newton Cross Calibration Archieve
3. Point spread function
The shape of the PSF core is different for all cameras:
(b) SPF for MOS2
(a) SPF for MOS1
Evaluation of the XMM Newton Cross Calibration Archieve

8. →50%lost at 10” (=200 xy coord)‏
3. Point spread function
Encircled energy as a function of radius from the centre of the PSF
PSF profile
→50%lost at 10” (=200 xy coord)‏
Evaluation of the XMM Newton Cross Calibration Archieve

9. Evaluation of the XMM Newton Cross Calibration Archieve
4. EPIC photon pile-up
Pile-up: Arrival of more than one photon within the readout time of the detectors
Pattern pile-up:
Two or more photons arriving next to each other in the same readout time.
Energy pile-up:
Two photons hitting the same pixel in the same readout.
Consequences:
Shifts the spectrum towards higher energies
Less counts at the PSF centre
Evaluation of the XMM Newton Cross Calibration Archieve

10. Loss of counts at the centre of the PSF
4. EPIC photon pile-up
The PSF is influenced by pile-up: too many photons arrive at the same time at the core of the PSF
clean PSF
Loss of counts at the centre of the PSF
→pile-up effect: artificial hole at its centre
Evaluation of the XMM Newton Cross Calibration Archieve

11. Evaluation of the XMM Newton Cross Calibration Archieve
5. OVERVIEW OF THE SCRIPT
(1) Download data from XMM-Newton Science Archive
(2) Define the source region and the background region
(3) Extract spectrum from all different annulli
(4) Find a suitable model for the source spectrum
(5) Spectral fitting for all the individual spectrum
(6) Compare results of the different annulli.
Evaluation of the XMM Newton Cross Calibration Archieve

12. Evaluation of the XMM Newton Cross Calibration Archieve
(2) Images from different regions
Evaluation of the XMM Newton Cross Calibration Archieve

13. (3) Spectra for different regions
Evaluation of the XMM Newton Cross Calibration Archieve

14. Evaluation of the XMM Newton Cross Calibration Archieve
6. FINAL RESULT
Evaluation of the XMM Newton Cross Calibration Archieve

15. Evaluation of the XMM Newton Cross Calibration Archieve
7. SUMMARY
All the parameters are identical (within errors) until ~20 arcsec: moderate pile-up does not affect scientific results.
General tool that makes everything automatically except: definition of source/background coordinates and spectral model of the source.
Why do we create this tool??
EPIC group is changing the model for the PSF: with this tool we check the results of the spectral analysis (→should be independent from the region we extract the data)‏
Evaluation of the XMM Newton Cross Calibration Archieve

16. Evaluation of the XMM Newton Cross Calibration Archieve
8. OUTLOOK
(a) Current model
(b) New model
Evaluation of the XMM Newton Cross Calibration Archieve

17. Evaluation of the XMM Newton Cross Calibration Archieve
Thanks to you all….
…. Any questions??
Evaluation of the XMM Newton Cross Calibration Archieve