ISSN:
1572-946X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We showed in earlier work that a clump embedded in tenuous plasma, which is flowing subsonically relative to the clump, will develop a long thin tail whether the gas in the tail behaves adiabatically or isothermally. This paper presents a criterion for determining if viscous dissipation in a tail with result in heating that will cause such a tail to be wide. We argue that the observed properties of the tails in NGC 7293 imply that a very strong effective viscous couple exists across each of them. Assuming a strong couple, we calculate the viscous energy dissipation rate per unit volume and derive an upper bound on the number density in a tail in which viscous heating raises the temperature significantly and thus causes broadening. The densities in observed broad tails in Abell 30 exceed this upper bound, and we suggest that the broadening of those tails is due to a phase transition in the tail gas, caused by photo-absorption heating. We comment on the relationship of intermediate-scale structures in clumpy media to the issue of whether or not a global tenous flow can be considered to be mass-loaded.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00643600
