Analytic Solutions for Truncated Plasmons

Abstract

We present a new plasmon model for a cometary clump moving supersonically in an environment with a non-zero gas pressure. We find that the environmental pressure produces a cutoff in the wings of the cometary clump, therefore resulting in quite "stubby" plasmons for a large range of flow Mach numbers. We derive a relation between the length-to-width ratio of the plasmon and the Mach number M of the flow, which could be used to directly derive M from observations of (appropriate) cometary clumps.

The Hii Regions and Bow Shocks Around Runaway O Stars

“…i.e., the square of the ion number density (n = ρ/m for fully ionized H and singly ionized He) integrated across the width h of the thin shell. This integral was calculated by Cantó et al (2005) for a bow shock travelling into an environment with a density gradient, and their results can be used (by setting the density gradient to zero) to obtain the emission measure for a bow shock in a uniform environment:…”

“…In this appendix we give the functions determining the angular dependence of the emission measure of the thin shell solution of equation ( 1). The functions that we give here correspond to the results of Cantó et al (2005) evaluated for the case of a uniform environment,…”

“…We describe the flow by considering the thin shell analytic solution (of Wilkin 1996;Cantó et al 1996 andCantó et al 2005) for the stellar wind bow shock. A review of this solution is presented in §2.…”