K. Robinson et al. 2004 ApJ 601 621 doi:10.1086/380817
K. Robinson1,2, L. J. Dursi2,3, P. M. Ricker4,5, R. Rosner2,3,6, A. C. Calder2,3, M. Zingale7, J. W. Truran2,3, T. Linde2,3, A. Caceres2,6, B. Fryxell2,3, K. Olson2,8, K. Riley2, A. Siegel2 and N. Vladimirova2
Show affiliationsRecent Chandra and XMM-Newton observations of galaxy cluster cooling flows have revealed X-ray emission voids of up to 30 kpc in size that have been identified with buoyant, magnetized bubbles. Motivated by these observations, we have investigated the behavior of rising bubbles in stratified atmospheres using the FLASH adaptive-mesh simulation code. We present results from two-dimensional simulations with and without the effects of magnetic fields and with varying bubble sizes and background stratifications. We find purely hydrodynamic bubbles to be unstable; a dynamically important magnetic field is required to maintain a bubble's integrity. This suggests that, even absent thermal conduction, for bubbles to be persistent enough to be regularly observed, they must be supported in large part by magnetic fields. Thermal conduction unmitigated by magnetic fields can dissipate the bubbles even faster. We also observe that the bubbles leave a tail as they rise; the structure of these tails can indicate the history of the dynamics of the rising bubble.
cooling flows; galaxies: clusters: general; hydrodynamics; instabilities; MHD; X-rays: galaxies: clusters
Issue 2 (2004 February 1)
Received 2003 April 30, accepted for publication 2003 October 17
K. Robinson et al. 2004 ApJ 601 621
M. Zingale et al. 2002 ApJS 143 539
B. Fryxell et al. 2000 ApJS 131 273
J. B. Bell et al. 2004 ApJ 608 883
A. C. Calder et al. 2002 ApJS 143 201
A. S. Almgren et al. 2008 ApJ 684 449
M. Zingale et al. 2001 ApJS 133 195
A. S. Almgren et al. 2006 ApJ 649 927
M Zingale et al 2006 J. Phys.: Conf. Ser. 46 385
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