How D-type HII region expansion depends on numerical resolution

Abstract

We investigate the resolution dependence of HII regions expanding past their Strömgren spheres. We find that their structure and size, and the radial momentum that they attain at a given time, is in good agreement with analytical expectations if the Strömgren radius is resolved with $dr\le 0.3R_{\mathrm{st}}$. If this is not satisfied, the radial momentum may be over- or under-estimated by factors up to 10 or more. Our work has significance for the amount of radial momentum that a HII region can impart to the ambient medium in numerical simulations, and thus on the relative importance of ionizing feedback from massive stars.

6 pages, 2 figures, accepted for publication in MNRAS

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Cited by in corpus (2)

• Simulating ionization feedback from young massive stars: impact of numerical resolution
• Momentum and energy injection by a wind-blown bubble into an inhomogeneous interstellar medium