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Formation of 'bullets' by hydrodynamical instabilities in stellar outflows

Abstract

IMAGES of young stars1 and supernova remnants2 often reveal small, high-density knots of material which are interpreted as 'bullets' ejected by the source and propagating at supersonic speeds into the surrounding interstellar medium. But it is unclear how these bullets could be created and accelerated without disrupting their structure. An alternative interpretation of these features is that they condense in situ in high-velocity stellar winds as a result of hydrodynamical instabilities—such mechanisms have been proposed to explain the condensations seen in supernova ejecta3, and may also operate in planetary nebulae. Here we show that similar processes can also form bullets in the poorly collimated winds from young stars. We therefore suggest that bullets associated with outflow sources should not, in general, be ascribed to explosive events at the source; rather, they form as a direct result of the interaction between the outflowing gas and the surrounding medium.

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References

  1. Allen, D. A. & Burton, M. G. Nature 363, 54–56 (1993).

    Article  ADS  Google Scholar 

  2. Strom, R., Johnston, H. M., Verbundt, F. & Aschenback, B. Nature 373, 590–592 (1995).

    Article  ADS  Google Scholar 

  3. Hester, J. J. et al. Astrophys. J. (in the press).

  4. Bachiller, R. & Gomez-Gonzales, J. Astr. Astrophys. Rev. 3, 257–287 (1992).

    Article  ADS  Google Scholar 

  5. Edwards, S., Ray, T. & Mundt, R. in Protostars and Planets III (ed. Levy, E. & Lunine, J.) 567–602 (Univ. Arizona Press, Tuscon, 1994).

    Google Scholar 

  6. Norman, C. & Silk, J. Astrophys. J. 228, 197–205 (1979).

    Article  CAS  ADS  Google Scholar 

  7. Stone, J. M. & Norman, M. L. Astrophys. J. 420, 237–246 (1994).

    Article  ADS  Google Scholar 

  8. de Gouveai Dal Pino, E. & Benz, W. Astrophys. J. 410, 686–695 (1993).

    Article  ADS  Google Scholar 

  9. Riepurth, B. Nature 340, 42–45 (1989).

    Article  ADS  Google Scholar 

  10. Stone, J. M. & Norman, M. L. Astrophys. J. 413, 210–220 (1993).

    Article  ADS  Google Scholar 

  11. Raga, A. C. Rev. Mex. Astr. Astrofys. serie de conferencias 1, 103–117 (1995).

    CAS  ADS  Google Scholar 

  12. Scoville, N., Kleinmann, S. G., Hall, D. N. B. & Ridgway, S. T. Astrophys. J. 275, 201–224 (1983).

    Article  CAS  ADS  Google Scholar 

  13. Genzel, R. & Stutzki, J. A. Rev. Astr. Astrophys. 27, 41–85 (1989).

    Article  CAS  ADS  Google Scholar 

  14. Bunn, J. C., Hoare, M. G. & Drew, J. E. Mon. Not. R. astr. Soc. 272, 346–354 (1995).

    Article  ADS  Google Scholar 

  15. Martì, J., Rodriguez, L. F. & Riepurth, B. Astrophys. J. 449, 184–187 (1995).

    Article  ADS  Google Scholar 

  16. Spitzer, L. Jr. Physical Processes in the Interstellar Medium (Wiley-lnterscience, New York, 1978).

    Google Scholar 

  17. Castor, J., McCray, R. & Weaver, R. Astrophys. J. 200, L107–L110 (1975).

    Article  CAS  ADS  Google Scholar 

  18. Weaver, R., McCray, R., Castor, J., Shapiro, P. & Moore, R. Astrophys. J. 218, 377–395 (1977).

    Article  CAS  ADS  Google Scholar 

  19. Koo, B. C. & McKee, C. Astrophys. J. 388, 93–102 (1992).

    Article  ADS  Google Scholar 

  20. MacLow, M.-M., McCray, R. & Norman, M. Astrophys. J. 337, 141–154 (1989).

    Article  ADS  Google Scholar 

  21. Tomisaka, K. & Ikeuchi, S. Astrophys. J. 330, 695–717 (1988).

    Article  CAS  ADS  Google Scholar 

  22. Gaetz, T., Edgar, R. J. & Chevalier, R. A. Astrophys. J. 329, 927–942 (1988).

    Article  ADS  Google Scholar 

  23. Howarth, I. & Prinja, R. K. Astrophys. J. Suppl. 69, 527–592 (1989).

    Article  CAS  ADS  Google Scholar 

  24. MacLow, M.-M. & Norman, M. L. Astrophys. J. 407, 207–218 (1993).

    Article  ADS  Google Scholar 

  25. Garciia-Segura, G., MacLow, M.-M. & Langer, N. Astr. Astrophys. (in the press).

  26. Tedds, J. A., Brand, P. W. J. L., Burton, M. G., Chrysostomou, A. & Fernandes, A. J. L. in Cloud Cores and Low Mass Stars (Clemens, D. P. & Barvainis, R.) 375–379 (Astr. Soc. Pacific Conf. Series, 65, San Francisco, 1995).

    Google Scholar 

  27. Staude, H. J. & Elsasser, H. Astr. Astrophys. Rev. 5, 165–238 (1993).

    Article  ADS  Google Scholar 

  28. Schwartz, R. D. et al. Astr. J. 106, 740–746 (1993).

    Article  CAS  ADS  Google Scholar 

  29. Gull, S. F. Mon. Not. R. astr. Soc. 161, 47–69 (1973).

    Article  ADS  Google Scholar 

  30. Chevalier, R. A. & Klein, R. Astrophys. J. 219, 994–1007 (1977).

    Article  ADS  Google Scholar 

  31. Herant, M. & Benz, W. Astrophys. J. 370, L81–L84 (1991).

    Article  CAS  ADS  Google Scholar 

  32. Harrington, P. Bull. Am. astr. Soc. 26, 1469 (1995).

    ADS  Google Scholar 

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Stone, J., Xu, J. & Mundy, L. Formation of 'bullets' by hydrodynamical instabilities in stellar outflows. Nature 377, 315–317 (1995). https://doi.org/10.1038/377315a0

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