X-ray Signature of Shock Modification in SN 1006

350 views
318 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
350
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
1
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

X-ray Signature of Shock Modification in SN 1006

  1. 1. X-ray signature of shock modification in SN 1006 Supernova Remnants and Pulsar Wind Nebulae in the Chandra Era July 8-10 2009, Boston, USA Marco Miceli Università di Palermo, INAF - Osservatorio Astronomico di Palermo Collaborators: F. Bocchino, D. Iakubovskyi, S. Orlando, I. Telezhinsky, M. Kirsch, O. Petruk, G. Dubner, G. Castelletti Miceli et al. X-ray emission of SN 1006, Boston 2009
  2. 2. Introduction We study the rim of SN 1006 to study how particle acceleration affects the structure of the remnant. We focus both on thermal and non-thermal X-ray emission. Aims: Physical and chemical properties of the X-ray emitting plasma to find Tracer of shock-modification (distance BW-CD, post-shock T, etc.) Data:  XMM-Newton archive observations (7 obs. in 2000-2005, ~7-30 ks each)  VLA and single dish radio data to constrain the non-th. radio flux (VLA AB, BC and CD in 1991-1992; Single dish Parkes in 2002 added; Synth. beam 7”.7x4”.8) Miceli et al. X-ray emission of SN 1006, Boston 2009
  3. 3. Spectral analysis We select 30 regions at the rim and adopt a unique model to explain different spectral properties in terms of azimuthal variations of best-fit parameters One thermal component in NEI + one non-thermal component (SRCUT) Te, τ, EM, abundances – NEI thermal component F1 GHz, νroll, α – non-thermal component (srcut, Reynolds 98) Miceli et al. X-ray emission of SN 1006, Boston 2009
  4. 4. What we do not see: the ISM Thermal component with oversolar abundances: we can detect the ejecta (see below), but where’s the shocked ISM? Is it too cold to emit X-rays? Or too tenous for the available statistics? If we add another thermal component to model the ISM emission the quality of the fit does not improve (even in “thermal” regions) and we have too many free parameters and useless results We cannot constrain signatures of shock modification in the thermodynamics of the post-shock ISM (low T, large n, etc.). Need for deeper observations (XMM LP, PI A. Decourchelle), see Gilles Mauren’s talk In literature the presence of ISM is controversial: Acero et al. (2007) find that at NW and SE (thermal regions) ISM is statistically not needed (if they include the SRCUT) and estimate kTISM~1.5 keV, while Yamaguchi et al. 2008 estimate that at SE kTISM~0.5 keV Miceli et al. X-ray emission of SN 1006, Boston 2009
  5. 5. What we see: 1) synchrotron emission  Profile of νbreak consistent with Rothenflug et al. (2003)  α~0.5 and values of νbreak in agreement with Allen et al. (2008) S W N E S W N E Miceli et al. X-ray emission of SN 1006, Boston 2009
  6. 6. What we see: 2) ejecta We determine the abundances in two large thermal regions: NW and SE Anisotropies in T and abundances Miceli et al. X-ray emission of SN 1006, Boston 2009
  7. 7. What we see: 2) ejecta Ejecta EM drops down in non-thermal limbs! SW limb NE limb kT(keV)τPS(cm-3 s)EM(cm-5 pc) Miceli et al. X-ray emission of SN 1006, Boston 2009
  8. 8. Pure thermal image  For each pixel we extrapolate the contribution of the non- thermal emission in the (0.5-0.8 keV band) from the image in the 2-4.5 keV band  The procedure relies only on the spectral results of the SRCUT component (robust and in agreement with those reported in literature Miceli et al. X-ray emission of SN 1006, Boston 2009
  9. 9. Pure thermal image SW limb NE limb Low values of EM in non-thermal limbs are naturally explained as volume effects Miceli et al. X-ray emission of SN 1006, Boston 2009
  10. 10. Blast wave – Contact Discontinuity Miceli et al. X-ray emission of SN 1006, Boston 2009 We determine the position of the blast wave shock from the 2-4.5 keV image and from the Hα map (Winkler et al. 2003). Same approach as Cassam-Chenai et al. (2008), but we use our thermal image in the 0.5-0.8 keV band to determine the position of the contact discontinuity
  11. 11. Blast wave – Contact Discontinuity
  12. 12. Comparison with MHD models 3-D MHD model of non-modified SNR shock (see S. Orlando’s talk) Model parameters: ejecta shock front 3-D simulations can model the Richtmyer-Meshkov instabilities and the “fingers” of ejecta Miceli et al. X-ray emission of SN 1006, Boston 2009
  13. 13. Comparison with MHD models γ=5/3 γ=4/3 γ=1.1 The shock is modified everywhere. No lower ratios in non-thermal limbs: we do not observe regions with larger efficiency of the acceleration processes edge-on. Aspect angle < 90º Miceli et al. X-ray emission of SN 1006, Boston 2009
  14. 14. Conclusions  No X-ray emission from the ISM  Revised values of α and νbreak  Inhomogeneities in the ejecta (temperature and abundances)  Pure thermal image of the ejecta  Azimuthal profile of BW/CD  Shock modified everywhere  Aspect angle < 90º (see F. Bocchino’s talk) Miceli et al. 2009, A&A, in press Miceli et al. X-ray emission of SN 1006, Boston 2009

×