X-ray signature of shock modification in SN 1006

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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
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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
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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, t, EM, abundances NEI
thermal component F1 GHz, nroll, a non-thermal
component (srcut, Reynolds 98)
Miceli et al. X-ray emission of SN 1006, Boston
2009
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What we do not see the ISM
Thermal component with oversolar abundances we
can detect the ejecta (see below), but wheres
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 Maurens 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 kTISM1.5 keV, while Yamaguchi et al.
2008 estimate that at SE kTISM0.5 keV
Miceli et al. X-ray emission of SN 1006, Boston
2009
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What we see 1) synchrotron emission
S W N
E
S W N
E

• Profile of nbreak consistent with Rothenflug et
  al. (2003)
• a0.5 and values of nbreak in agreement with
  Allen et al. (2008)

Miceli et al. X-ray emission of SN 1006, Boston
2009
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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
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What we see 2) ejecta
SW limb NE limb
kT (keV) tPS (cm-3 s)
EM (cm-5 pc)
Ejecta EM drops down in non-thermal limbs!
Miceli et al. X-ray emission of SN 1006, Boston
2009
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What we see 2) ejecta
Miceli et al. X-ray emission of SN 1006, Boston
2009
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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
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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
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Pure thermal image test 2
Emission measure per unit area (preliminary
analysis performed on the new XMM-Newton LP data
(PI A. Decourchelle)
0.0320.002 cm-6 pc
0.0030.002 cm-6 pc 0.0140.002 cm-6 pc
0.0010.001 cm-6
pc 0.0090.003 cm-6 pc
e
3
1
4
2
0.5-0.8 keV Total
0.5-0.8 keV Thermal
3
1
4
e
2
Miceli et al. X-ray emission of SN 1006, Boston
2009
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Pure thermal image test 3
Miceli et al. X-ray emission of SN 1006, Boston
2009
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Blast wave Contact Discontinuity
We determine the position of the blast wave shock
from the 2-4.5 keV image and from the Ha 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
Miceli et al. X-ray emission of SN 1006, Boston
2009
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Blast wave Contact Discontinuity
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Comparison with MHD models
shock front
3-D MHD model of non-modified SNR shock (see S.
Orlandos talk)
3-D simulations can model the Richtmyer-Meshkov
instabilities and the fingers of ejecta
Model parameters

ejecta
Miceli et al. X-ray emission of SN 1006, Boston
2009
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Comparison with MHD models
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 lt 90º
Miceli et al. X-ray emission of SN 1006, Boston
2009
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Conclusions

• No X-ray emission from the ISM
• Revised values of a and nbreak
• Inhomogeneities in the ejecta (temperature and
  abundances)
• Pure thermal image of the ejecta
• Azimuthal profile of BW/CD
• Shock modified everywhere
• Aspect angle lt 90º (see F. Bocchinos talk)

Miceli et al. 2009, AA, in press
Miceli et al. X-ray emission of SN 1006, Boston
2009