Bow shock fragmentation driven by a thermal instability in laboratory-astrophysics experiments
Abstract
The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counter-streaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame and the experiments are driven over many times the characteristic cooling time-scale. The initially smooth bow shock rapidly develops small-scale non-uniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.
Keywords
Cite
@article{arxiv.1509.06538,
title = {Bow shock fragmentation driven by a thermal instability in laboratory-astrophysics experiments},
author = {F. Suzuki-Vidal and S. V. Lebedev and A. Ciardi and L. A. Pickworth and R. Rodriguez and J. M. Gil and G. Espinosa and P. Hartigan and G. F. Swadling and J. Skidmore and G. N. Hall and M. Bennett and S. N. Bland and G. Burdiak and P. de Grouchy and J. Music and L. Suttle and E. Hansen and A. Frank},
journal= {arXiv preprint arXiv:1509.06538},
year = {2015}
}
Comments
9 pages, 5 figures, Accepted for publication in The Astrophysical Journal on 5th November 2015