Energetics of star-disc encounters in the non-linear regime

S. M. Hall; C. J. Clarke; J. E. Pringle

doi:10.1093/mnras/278.2.303

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arXiv · astro-ph/9510153

Energetics of star-disc encounters in the non-linear regime

S. M. Hall·C. J. Clarke·J. E. Pringle

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Abstract

We investigate the response of a circumstellar accretion disc to the fly-by of a perturbing mass on a parabolic orbit. The energy and angular momentum transferred during the encounter are calculated using a reduced three-body method. In almost all close encounters the energy and angular momentum transfer is dominated by disc material becoming unbound from the system, with the contributions from close disc particle -- star encounters being significant. For more distant encounters with some prograde element to the motion the disc material loses energy and angular momentum to the perturber's orbit through a resonance feature. The magnitude of the energy transfer calculated in our simulations is greater than that of the binding energy of material exterior to periastron by a factor of two in the prograde case, and up to a factor of five in the case of the retrograde encounter. The destructive nature of the encounters indicates that a non-linear treatment is essential in all but the most distant encounters.

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S. M. Hall, C. J. Clarke, J. E. Pringle. 1995-10-31. Energetics of star-disc encounters in the non-linear regime. https://doi.org/10.1093/mnras%2F278.2.303

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