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Paper: |
MHD Simulations of a Supernova-driven ISM and the Warm Ionized
Medium Using a Positivity Preserving Ideal MHD Scheme |
Volume: |
459, 6th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2011) |
Page: |
112 |
Authors: |
Low, M.-M. M.; Hill, A. S.; Joung, M. R.; Waagan, K.; Klingenberg, C.; Wood, K.; Benjamin, R. A.; Federrath, C.; Haffner, L. M. |
Abstract: |
We present new 3D magnetohydrodynamic (MHD) simulations of a
supernova-driven, stratified interstellar medium. These simulations
were run using the Waagan (2009)
positivity preserving scheme
for ideal MHD implemented in the Flash code. The scheme is stable even
for the Mach numbers approaching 100 found in this problem. We have
previously shown that the density distribution arising from
hydrodynamical versions of these simulations creates low-density
pathways through which Lyman continuum photons can travel to heights
|z| > 1 kpc. This naturally produces the warm ionized medium through
photoionization due primarily to O stars near the plane. However, our
earlier models reproduce the peak but not the width of the observed
emission measure distribution. Here, we examine whether inclusion of
magnetic fields and a greater vertical extent to the simulation domain
produce a gas distribution that better matches the observations. We
further study the change of magnetic energy over time in our models,
showing that it appears to reach a steady state after a few hundred
megayears, presumably supported by a turbulent dynamo driven by the
supernova explosions. |
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