Title:	Size distribution of superbubbles
Authors:	Nath, Biman B. Das, Pushpita Oey, M.S.
Keywords:	ISM bubbles –HII regions – ISM structure – galaxies: ISM
Issue Date:	Mar-2020
Publisher:	Oxford University Press on behalf of the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2020, Vol.493, p1034–1043
Abstract:	We consider the size distribution of superbubbles in a star-forming galaxy. Previous studies have tried to explain the distribution by using adiabatic self-similar evolution of wind-driven bubbles, assuming that bubbles stall when pressure equilibrium is reached. We show, with the help of hydrodynamical numerical simulations, that this assumption is not valid. We also include radiative cooling of shells. In order to take into account non-thermal pressure in the ambient medium, we assume an equivalent higher temperature than implied by thermal pressure alone. Assuming that bubbles stall when the outer shock speed becomes comparable to the ambient sound speed (which includes non-thermal components), we recover the size distribution with a slope of ∼−2.7 for typical values of interstellar medium pressure in Milky Way, which is consistent with observations. Our simulations also allow us to follow the evolution of size distribution in the case of different values of non-thermal pressure, and we show that the size distribution steepens with lower pressure, to slopes intermediate between only-growing and only-stalled cases.
Description:	Open Access
URI:	http://hdl.handle.net/2289/7469
ISSN:	0035-8711 1365-2966 (online)
Alternative Location:	https://ui.adsabs.harvard.edu/abs/2020arXiv200410214N/abstract https://doi.org/10.1093/mnras/staa336
Copyright:	2020 The Author(s)
Appears in Collections:	Research Papers (A&A)

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