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On the structure of tidally disrupted stellar debris streams

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journal contribution
posted on 13.05.2016, 15:17 by Eric R. Coughlin, Chris J. Nixon, Mitchell C. Begelman, Philip J. Armitage
A tidal disruption event (TDE) – when a star is destroyed by the immense gravitational field of a supermassive black hole – transforms a star into a stream of tidally shredded debris. The properties of this debris ultimately determine the observable signatures of tidal disruption events (TDEs). Here we derive a simple, self-similar solution for the velocity profile of the debris streams produced from TDEs, and show that this solution agrees extremely well with numerical results. Using this self-similar solution, we calculate an analytic, approximate expression for the radial density profile of the stream. We show that there is a critical adiabatic index that varies as a function of position along the stream above (below) which the stream is unstable (stable) to gravitational fragmentation. We also calculate the impact of heating and cooling on this stability criterion.

Funding

This work was supported in part by NASA Astrophysics Theory Program grants NNX14AB37G and NNX14AB42G, NSF grant AST-1411879, and NASA’s Fermi Guest Investigator Program. CN was supported by the Science and Technology Facilities Council (grant number ST/M005917/1).

History

Citation

Monthly Notices of the Royal Astronomical Society, 2016, 459 (3), pp. 3089-3103

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society

Publisher

Oxford University Press (OUP) on behalf of the Royal Astronomical Society

issn

0035-8711

eissn

1365-2966

Acceptance date

30/03/2016

Copyright date

2016

Available date

13/05/2016

Publisher version

http://mnras.oxfordjournals.org/content/459/3/3089

Notes

Deposited with reference to the publisher’s open access archiving policy.

Language

en