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SPIRAL SHOCK TRIGGERING OF STAR FORMATION

  • Ian A. Bonnel
  • Clare L. Dobbs
Part of the Astrophysics and Space Science Proceedings book series (ASSSP)

Abstract

We present numerical simulations of the passage of clumpy gas through a galactic spiral shock and the subsequent formation of giant molecular clouds (GMCs) and the triggering of star formation. The spiral shock formsdense clouds while dissipating kinetic energy, producing regions that are locally gravitationally bound and collapse to form stars. In addition to triggering the star formation process, the clumpy gas passing through the shock naturally generates the observed velocity dispersion size relation ofmolecular clouds. In this scenario, the internal motions of GMCs need not be turbulent in nature. The coupling of the clouds’ internal kinematics totheir externally triggered formation removes the need for the clouds to beself-gravitating. Globally unbound molecular clouds provides a simple explanation of the low efficiency of star formation. While dense regions in the shock become bound and collapse to form stars, the majority of the gas disperses as it leaves the spiral arm.

Keywords

Star Formation Smooth Particle Hydrodynamic Velocity Dispersion Molecular Cloud Spiral Galaxy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Baade, W., 1963, Evolution of stars and Galaxies, Harvard University press (Cambridge), p 63.Google Scholar
  2. Bate M. R., Bonnell I. A., Price N. M., 1995, MNRAS, 277, 362.ADSGoogle Scholar
  3. Blitz, L. & Williams, J., 1999, The origin of stars and planetary systems, eds C.J.Lada, N.D. Kylafis, (Kluwer:Dordrecht), 3Google Scholar
  4. Bonnell, I.A., Dobbs, C.L., Robitaille, T.P., Pringle, J.E., 2005, MNRAS, submittedGoogle Scholar
  5. Clark, P.C., Bonnell, I.A., 2004 MNRAS, 347, L36CrossRefADSGoogle Scholar
  6. Clark, P.C., Bonnell, I.A., Zinnecker, H., Bate, M.R., 2004 MNRAS, 359, 809CrossRefADSGoogle Scholar
  7. Cowie L. L., 1981, ApJ, 245, 66CrossRefADSGoogle Scholar
  8. Elmegreen B. G., 1991, ApJ, 378, 139CrossRefADSGoogle Scholar
  9. Elmegreen B. G., Elmegreen D. M., 1983, MNRAS, 203, 31ADSGoogle Scholar
  10. Elmegreen B., Scalo, J., 2004, ARA&A, 42, 211ADSCrossRefGoogle Scholar
  11. Ferguson A. M. N., Wyse R. F. G., Gallagher J. S., Hunter D. A., 1998, ApJ, 506, L19CrossRefADSGoogle Scholar
  12. Heyer M. H., Brunt C. M., 2004, ApJ, 615, 45CrossRefADSGoogle Scholar
  13. Larson R. B., 1981, MNRAS, 194, 809.ADSGoogle Scholar
  14. Mac Low, M.M., Klessen, R.S., 2004, RvMP, 74, 125ADSGoogle Scholar
  15. Monaghan J. J., 1992, ARA&A, 30, 543.ADSCrossRefGoogle Scholar
  16. Roberts, W.W., 1969, ApJ, 158, 123CrossRefADSGoogle Scholar

Copyright information

© Springer 2007

Authors and Affiliations

  • Ian A. Bonnel
    • 1
  • Clare L. Dobbs
    • 1
  1. 1.Dept. of Physics and AstronomyUniversity of St AndrewsScotland

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