All Questions
Tagged with shock-waves astrophysics
14 questions
12
votes
1
answer
2k
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Shock when a supernova explodes
I have been reading that when supernovae explode, they produce (Shockwaves) which act as cosmic accelerators.
I do not understand, what is meant with "shock" (partially because I do not ...
- 361
4
votes
2
answers
118
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Plage regions data
Plages are phenomena of stellar activity.
Where can I find openly-accessible data of plage regions of the Sun with other parameters such as faculae region, magnetic field, etc?
- 193
2
votes
1
answer
97
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Is the internal energy of a supernova blast wave always 72% of the initial energy released?
In Astrophysics, an A-Z Introduction, Page 67, Patrick Betts states that in the Sedov-Taylor solution for a blast wave, the temperature of a supernova shell decreases over time, but the internal ...
- 73
3
votes
1
answer
75
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How can supersonic accretion flows exist in astrophysical scenarios?
I often hear about supersonic accretion flows in astrophysical scenarios: for example, the inner parts of the accretion disk around a supermassive black hole or cold filaments accreting into galaxies ...
- 205
2
votes
1
answer
64
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Interaction of supersonic wind with static Inter-Stellar Medium (ISM)
Recently I was studying about the interaction of supersonic flow (wind) with a slowly flowing medium. In a paper by Dyson, Falle, and Perry 1980 MNRAS stated that when a supersonic wind impinged upon ...
- 97
2
votes
1
answer
88
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What is the most efficient particle acceleration mechanism in space and astrophysical plasmas
My question is:
What are the most efficient particle acceleration mechanisms in space and astrophysical plasmas: wave-particle interactions, collisionless shocks, or magnetic reconnection?
Does it ...
- 490
0
votes
1
answer
46
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Physical reason behind the origin of shock waves in astrophysics [duplicate]
Shock waves arises in astrophysics in accretion flows and in winds. But we know that shock waves usually occurs in supersonic flows when the flow encounters any obstacle or when the properties of the ...
- 2,065
3
votes
1
answer
168
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Importance of speed of sound in astrophysical flows
The speed of sound is very important in astrophysics in the study of accretion and wind flows. I have two questions as follows:
What is special about the speed of sound and not any other value of ...
- 2,065
2
votes
1
answer
71
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Derivation of average momentum change in diffusive shock acceleration
I am trying to figure out a specific step in the derivation of the power law spectrum for cosmic ray particles upon diffusive shock acceleration. I am working with Drury 1983 (pdf link) but I have ...
- 21
1
vote
1
answer
178
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Bulk viscosity in jump conditions for shock waves
One of the jump conditions for shock waves can be derived from the Navier-Stokes equation and it takes the form (see Shu, Gas dynamics, p.212)
$\dfrac{d}{dx}\left(\rho u^2 + P - \frac{4}{3}\mu \frac{...
- 111
3
votes
2
answers
724
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A question about the Fermi acceleration
In high school physics, we know that a charged particle cannot gain energy from a magnetic field. But, it seems that in the so-called Fermi acceleration, the particle is accelerated by the magnetic ...
- 1,075
3
votes
1
answer
381
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Mach no. should be constant for existence of similarity solution
I am reading some research papers on Taylor-Sedov type self-similar solution to the blast wave problems...
It is written that for the existence of similarity solutions Mach number should be constant.....
- 83
1
vote
1
answer
87
views
Relativistic blast waves in medium of non uniform density
The relativistic outflow of a gamma ray burst drives a shock into the circumburst medium. This medium could have a uniform density $n_0$ or a density profile of the form, $n(r) \propto r^{-2}$.
For ...
- 331
5
votes
3
answers
1k
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How do shock waves form in space?
Today my aerodynamics professor mentioned that the equations we were learning for atmospheric shock waves can also be applied by astrophysicists to study black hole-related shock waves in space.
How ...
- 161