Non-Maxwellian Velocity Distributions on Tycho

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Non-Maxwellian Velocity Distributions on Tychos
SNR
J.C. Raymond, P.F. Winkler, W.P. Blair, J.J. Lee,
S. Park
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Balmer lines Profiles H? from H atoms excited
before Charge Transfer form Narrow Component. H?
from atoms excited after Charge Transfer form
Broad Component.
e-
Ghavamian et al. 2002
H I
Narrow Component Unresolved Broad post-shock
f(v)? (weighted by ?CX
Heng McCray)?
proton
Shock
h?
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Tychos SNR Shock
MMT slit positions Also HET spectra of 4
positions
HST Lee et al.
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2 and 3 Gaussian fits to profile

• FWHM 1540 km/s
• ?V 120 km/s

• FWHM 1160, 2230 km/s
• ?V 115, 140 km/s

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Explanations Superposition of different Proton
Temperatures along LOS Fits give factor of 2
difference in FWHM, which implies factor of 4
in n0 Implies rapid changes in
morphology Charge Transfer velocity dependence
Heng, van Adelsberg, McCray Cuts off
wings rather than enhances, but sums
different profiles. Looks like Gaussian for
2000 km/s
Van Adelsberg et al.
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MORE Explanations Modified Shock Continuous
range of T Blends Narrow Broad components?
Subshock jump could be 2X. Power Law Tail
Vladimirov et al.
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Non-Maxwellian Proton Distributions
Potentially Important
for Injection as well as Diagnostics Neutrals
ionized downstream are like Pickup Ions (Related
to ACRs)?
VS/4
VS
VPERP ¾ VS Sin? VPAR ¾ VS Cos?
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Proton Velocity Distribution
Bispherical Velocity Distribution
Thermal Pickup Distribution
Raymond, Isenberg Laming
Formation of bispherical distribution transfers
energy to waves may heat protons or electrons.
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Better fit than two Gaussians Not as good as
three, but fewer free parameters Parameter space
not fully explored
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In Conclusive Good enough
data reveal non-Gaussian profiles Superposition
of different T must happen at some level Pickup
Ion profiles must be present at some
level Charge transfer distortion of profile
probably not important in Tycho CR modified
shock temperature profile might contribute Power
law tail due to acceleration might contribute