Shadows behind Neutral Clumps in Photoionized Regions

Abstract
Shadows behind neutral clumps in photoionized regions can have a neutral core surrounded by gas that is photoionized by the diffuse flux produced by the nebula. We present a simple analytic model describing the configuration of such shadows. We also present numerical gasdynamic simulations of the relaxation to the final, steady state. These models have clear applications (e.g., to the cometary knots in the Helix Nebula) but can also be applied in other astrophysical contexts.

This publication has 11 references indexed in Scilit: