Photoionized stellar wind bubbles in a cloudy medium
C. F. McKee, D. ^vansBuren, B. Lazareff;
ApJ, 1984, 278, L115
ABSTRACT:The evolution of a stellar wind bubble in a cloudy medium of 1-10/cu cm mean density is investigated, allowing for the effects of the star's
ionizing radiation.
The dynamics of the bubble are governed by the effects of
photoionization: weak winds produce bubbles which are confined by the pressure of the H II
region, whereas strong winds produce bubbles whose size is determined by the
photoevaporation and displacement of the clouds.
Nebulae around massive stars begin
with wind-blown shells, evolve into amorphous H II regions, then ring-like
H II regions, then nebulae with stellar ejecta, and finally are swept up
by a blast wave when the star explodes as a supernova.
Part or all of the
ring-like phase may be too faint to observe.
Expanding H II shells with masses of
the order of 10,000 solar masses are predicted around massive stars, and
may account for the shells seen around the supernova remnants HB 21 and
W44.
KEYWORDS: interstellar gas, nebulae, photoionization, stellar winds, bubbles, h ii regions, stellar evolution, supernova remnants
PERSOKEY:region hii, ,
CODE: mckee84