Supernova Remnants
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When massive stars exhaust their supply of nuclear fuel they contract rapidly under gravity, and this initiates a supernova explosion. The outer layers of the star rebound and are expelled into space at high velocity (10,000's km/s), leaving a neutron star or black hole behind. The ejecta sweeps up the material in interstellar space, and is in turn slowed down, and a supernova remnant forms. The remnant may expand for 100,000's of years, before gradually merging into and becoming indistinguishable from the rest of the galaxy. S147, shown right, is an example of a fairly old SNR (100,000 yr). I have explored the evolution of a SNR located in close proximity to an active galactic nucleus (AGN), and the conditions needed for cool gas to form. |
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Superwinds
Very large galactic scale bubbles can be blown by the joint effects of winds and supernovae from large groups of massive stars. The hot gas generated by the collisions of winds and supernovae remnants can be driven out of galaxies in fast (a thousand km per second or so) 'superwinds', such as shown below in M82. In order to model these superwinds, it is necessary to consider complex interactions between the winds, the explosions and the interstellar gas. In a recent paper I explored the range of supernova remnants (SNRs) which over-run a clumpy medium, as a first step to understanding this process.
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