Supernova Remnants: An Odyssey in Space after Stellar death

Supernova Remnants: An Odyssey in Space after Stellar death

Supernova Remnants: An Odyssey in Space after Stellar death

Parviz

1st Abstract

Title (1st Abstract)

Electron-Ion Thermal Equilibration in Collisionless Shocks

First Author

Parviz Ghavamian

Affiliation

Towson University

Presentation options

Invited Talks

Session

5. Collisionless shock waves in SNRs

1st Abstract

Collisionless shocks are loosely defined as shocks where the transition between pre-and post-shock states happens on a length scale much shorter than the collisional mean free path. In this talk I review our state of knowledge regarding electron heating in astrophysical shocks, mainly associated with supernova remnants (SNRs). Observations of non-radiative SNRs indicate that the ratio of electron temperature, (Te), to ion temperature (Tp), declines with increasing shock speed. Such behavior can be understood on the basis of cosmic-ray driven waves generated by cosmic rays in a shock precursor. The damping of these waves heats electrons to a nearly constant energy, resulting in the observed decline in Te/Tp with shock speed. Similar mechanisms may work in supernova ejecta shocks and solar wind shocks, though with different scaling between Te/Tp and and shock speed.