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Journal of Physical Studies 15(3), Article 3901 [8 pages] (2011)
DOI: https://doi.org/10.30970/jps.15.3901 THE INFLUENCE OF STELLAR WIND BUBBLES ON THE RADIATION IONIZING FIELD IN THE NEBULAR OBJECTSB. Ya. Melekh1, I. O. Koshmak2, R. V. Kozel3
Ivan Franko National University of Lviv, Department of
Astrophysics, |
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Stellar superwind around the starbursts forms cavities with a low density of hot gas, thermalized by inverse wind shock. Young starbursts could contain compact cavities inside the Н{\sc ii} region. Diffuse ionizing radiation that arises in the cavity could affect the ambient medium ionization quite considerably. Outside the stellar wind bubble lies a thin shell swept-up by the direct wind shock. This shell and at certain conditions, when there is gas in the cavity, could appreciably transform the shape of the ionizing spectrum that drives into the surrounding region. The distribution of density values and other physical parameters of ‟bubble-like” structures were given by Weaver {\em et al.} in 1977. We decided to investigate using multicomponent photoionization modelling the influence of such ‟bubbles” on the ionization spectrum shape. The input spectrum of ionizing radiation was obtained from the starburst model with parameters typical for blue compact dwarf galaxies. Also, the `bubbles' around single stars were investigated. The first and second inner components of such a modelling correspond to the hypersonic stellar wind zone and the region of shocked stellar wind, respectivly. The gas density distribution in these components is derived from the bubble structure obtained from the equations system of continuity and energy transfer including heat conductivity. The third component is a thin shell of high density gas swept-up by the wind shock. The gas density in this component was obtained from the isobaric condition at a contact discontinuity between the second and third components. The evolution grid of multicomponent photoionization models with different `bubble' parameters was calculated. The influenсe of a thin high density shell on the spectrum was analysed.
PACS number(s): 98.58.Hf, 98.52.Wz, 98.54.Ep, 98.56.Wm