1. A large XMM-Newton project on SN 1006
Gilles Maurin
(Sap – IRFU/CEA-Saclay)
A. Decouchelle, G. Dubner, M. Miceli and the LP team

2. Why study SN 1006 ?
ATCA – 1.3 GHz
SN 1006 is a historical SNR: distance (2.2 kpc) and age are well-known
The interstellar absorption towards it is low
Uniform ambient medium around the source: its morphology is relatively symmetrical
Synchrotron observed from radio to X-rays
+ recently observed by H.E.S.S. in TeV γ-rays
XMM – 2-4 keV
H.E.S.S. - γ-rays
For all these reasons, SN1006 is a good target to study
particle acceleration

3. The objectives of the large XMM-Newton project
Where are the ejecta and what are they made of ?
Where is the shocked interstellar medium ?
How efficient is the proton acceleration ?
How is the shock energy shared between the different species at shock ?
What is the intensity and post-shock evolution of the downstream magnetic field ?
What are the maximum energies of accelerated electrons and ions ?
What is the geometry of the ambient magnetic field ?
We asked for a deep 1 Ms XMM-Newton observation of the entire SN 1006 supernova remnant
We obtained 500 ks
Outline of this présentation:
Data;
Analysis;
Preliminary result: study of the thermal and non- thermal emission around the shock

4. Status before the large project
7 observations between 2000 and 2005
Region
Clean time (ks) NE 31 SE 17 SW 28 NW 30
= 106 ks

5. Statistics are increased by a factor 5 in observed regions
The large project
6 new observations ( )
Region
Clean time (ks) NE 31
+ 135 SE 17
+ 149 SW 28 NW 30
+ 159
= 549 ks
Statistics are increased by a factor 5 in observed regions 
Will allow us to study the spectra of the non-thermal filaments around the shock

6. Standard method for background spectrum estimation
Blank sky for
PN instrument
Blank sky are used to estimate:
- astrophysical backgrounds
(local and extra-galactic photons background)
- particle background (CR and protons from solar)
(linked to the solar activity)
The rate of the particle background has strongly increased since 2005 (revolution 700). PN
Counts per second
MOS
We have to take into account this effect, in particular for the new observations ( ).
Revolution
2005
2009

7. Our method for background estimation
Closed observations
for PN instrument
Observations in closed mode are used to estimate the particle background
Double-substraction method are used to take into account the astrophysical background
Before stacking observations in closed-mode (to have high statistics), we checked that the spectrum of particle background didn’t change significantly with time.
Emission line
keV
Continuum
2 – 3 keV
Revolution = 500
Revolution = 1200
MOS
count rate (s-1) PN PN
MOS
Total count rate (s-1)

8. New images* from SN1006 with MOS instruments
*Background used = Closed observations
Regions used for astrophisical background estimation
2 - 4 keV
(dominated by non-thermal emission)
keV
(oxygen band)
 Spectrum extraction in 30 regions around the shock (like Miceli et al. 2009)

9. Examples of spectra Zone 29 In the SE region Zone 23 In the NE regionPN PN
MOS 1&2
MOS 1&2
Emission dominated by
thermal emission
Emission dominated by
synchrotron emission
10 spectra for MOS
4 spectra for PN
10 spectra for MOS
5 spectra for PN

10. Azimuthal behaviour Miceli et al. Our results Norm Models used:
VPSHOCK + SRCUT
Thermal model
VPSHOCK
The SRCUT normalization at 1 Ghz has been fixed by extracting the radio flux from the same region in the X-ray map: VLA observations (Petruk et al 2008)
kt (keV)
Comparison between the results from Miceli. et al.
and our method with the same observations:
 possible because the particle background is about constant in these observations. α
Non Thermal model
SRCUT
Very good agreement between the two results:
- confirms the results of Miceli et al.
- allows us to add new observations
Log(νbreak)
 High statistic allows us to reduce the size of the boxes

11. Azimuthal behaviour in the NE region
We divided each box in the
NE region by 10.
Thermal model
VPSHOCK
kt (keV) α
Non Thermal model
SRCUT
Evidence of small scale azimuthal variations of the non-thermal emission
Log(νbreak)
Now we have to follow precisely the spectral variations along the filamentary structures

12. Conclusion and outlook
We took into account properly the increase of particle background by using closed observations instead of blank sky.
We studied the azimuthal variations of the physical properties around the shock.
⇒ Our results are compatible with the previous ones
In the NE region, we revealed variations at small scale of the non-thermal emission
The statistic of the large project will allow us to study the acceleration parameters at the size of non-thermal filaments
NE - region
∼20’’
Statistics + angular resolution of XMM-Newton (∼8’’)
⇒ sufficient separation of the filaments
Coming soon