x-ray signature of shock modification in sn 1006
DESCRIPTION
Supernova Remnants and Pulsar Wind Nebulae in the Chandra Era July 8-10 2009, Boston, USA. X-ray signature of shock modification in SN 1006. Marco Miceli Università di Palermo, INAF - Osservatorio Astronomico di Palermo. Collaborators: - PowerPoint PPT PresentationTRANSCRIPT
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
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
Spectral analysisWe 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, , EM, abundances – NEI thermal component
F1 GHz, roll, – non-thermal component (srcut, Reynolds 98)
Miceli et al. X-ray emission of SN 1006, Boston 2009
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
What we see: 1) synchrotron emission
Profile of break consistent with Rothenflug et al. (2003) ~0.5 and values of break 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
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
What we see: 2) ejecta
Ejecta EM drops down in non-thermal limbs!
SW limb NE limb
kT (
keV
)
P
S (
cm-3 s
)
E
M (
cm-5 p
c)
Miceli et al. X-ray emission of SN 1006, Boston 2009
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
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
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 H 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
Blast wave – Contact Discontinuity
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
Comparison with MHD models
5/3
4/3
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
Conclusions
No X-ray emission from the ISM
Revised values of and break
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 pressMiceli et al. X-ray emission of SN 1006, Boston 2009