Bow shock fragmentation driven by a thermal instability in laboratory-astrophysics experiments
| Autor: | Suzuki-Vidal, F., Lebedev, S. V., Ciardi, A., Pickworth, L. A., Rodriguez, R., Gil, J. M., Espinosa, G., Hartigan, P., Swadling, G. F., Skidmore, J., Hall, G. N., Bennett, M., Bland, S. N., Burdiak, G., de Grouchy, P., Music, J., Suttle, L., Hansen, E., Frank, A. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/815/2/96 |
| Popis: | 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. Comment: 9 pages, 5 figures, Accepted for publication in The Astrophysical Journal on 5th November 2015 |
| Databáze: | arXiv |
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