Creasey, P. and Theuns, Tom and Bower, R.G. and Lacey, C.G. (2011) 'Numerical overcooling in shocks.', Monthly notices of the Royal Astronomical Society., 415 (4). pp. 3706-3720.
We present a study of cooling in radiative shocks simulated with smoothed particle hydrodynamics and adaptive mesh refinement codes. We obtain a similarity solution for a shock-tube problem in the presence of radiative cooling, and test how well the solution is reproduced in GADGET and FLASH. Shock broadening governed by the details of the numerical scheme (artificial viscosity or Riemann solvers) leads to potentially significant overcooling in both codes. We interpret our findings in terms of a resolution criterion, and apply it to realistic simulations of cosmological accretion shocks on to galaxy haloes, cold accretion and thermal feedback from supernovae or active galactic nuclei (AGN). To avoid numerical overcooling of accretion shocks on to haloes that should develop a hot corona a particle or cell mass resolution of 106 M⊙ is required, which is within reach of current state-of-the-art simulations. At this mass resolution, thermal feedback in the interstellar medium of a galaxy requires temperatures of supernova- or AGN-driven bubbles to be in excess of 107 K at densities of nH= 1.0 cm−3, in order to avoid spurious suppression of the feedback by numerical overcooling.
|Keywords:||Hydrodynamics shock waves methods, Numerical galaxies, Formation galaxies, ISM.|
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|Publisher Web site:||http://dx.doi.org/10.1111/j.1365-2966.2011.19001.x|
|Publisher statement:||This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.|
|Record Created:||14 Dec 2014 10:50|
|Last Modified:||03 Jun 2015 09:49|
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