Title:	In a hot bubble: why does superbubble feedback work, but isolated supernovae do not?
Authors:	Sharma, Prateek Roy, Arpita Nath, Biman B. Shchekinov, Yuri
Keywords:	shock waves bubbles ISM Supernova remnants galaxies ISM
Issue Date:	1-Oct-2014
Publisher:	Oxford University Press for the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2014, Vol. 443, p3463-3476
Abstract:	Using idealized one-dimensional Eulerian hydrodynamic simulations, we contrast the behaviour of isolated supernovae with the superbubbles driven by multiple, collocated supernovae. Continuous energy injection via successive supernovae exploding within the hot/dilute bubble maintains a strong termination shock. This strong shock keeps the superbubble overpressured and drives the outer shock well after it becomes radiative. Isolated supernovae, in contrast, with no further energy injection, become radiative quite early (≲0.1 Myr, tens of pc), and stall at scales ≲100 pc. We show that isolated supernovae lose almost all of their mechanical energy by 1 Myr, but superbubbles can retain up to ∼40 per cent of the input energy in the form of mechanical energy over the lifetime of the star cluster (a few tens of Myr). These conclusions hold even in the presence of realistic magnetic fields and thermal conduction. We also compare various methods for implementing supernova feedback in numerical simulations. For various feedback prescriptions, we derive the spatial scale below which the energy needs to be deposited in order for it to couple to the interstellar medium. We show that a steady thermal wind within the superbubble appears only for a large number (≳104) of supernovae. For smaller clusters, we expect multiple internal shocks instead of a smooth, dense thermalized wind.
Description:	Open Access
URI:	http://hdl.handle.net/2289/6168
ISSN:	0035-8711 1365-2966 - (online)
Alternative Location:	http://adsabs.harvard.edu/abs/2014MNRAS.443.3463S http://arxiv.org/abs/1402.6695 http://dx.doi.org/10.1093/mnras/stu1307
Copyright:	2014 The authors & the Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

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