Coughlin, E.R. orcid.org/0000-0003-3765-6401, Nixon, C.J. orcid.org/0000-0002-2137-4146 and Miles, P.R. orcid.org/0000-0003-1354-1984 (2020) The Persistence of Pancakes and the Revival of Self-gravity in Tidal Disruption Events. The Astrophysical Journal Letters, 900 (2). L39. ISSN 2041-8205
Abstract
The destruction of a star by the tides of a supermassive black hole (SMBH) powers a bright accretion flare, and the theoretical modeling of such tidal disruption events (TDEs) can provide a direct means of inferring SMBH properties from observations. Previously it has been shown that TDEs with β = rt/rp = 1, where rt is the tidal disruption radius and rp is the pericenter distance of the star, form an in-plane caustic, or "pancake," where the tidally disrupted debris is compressed into a one-dimensional line within the orbital plane of the star. Here we show that this result applies generally to all TDEs for which the star is fully disrupted, i.e., that satisfy β ≳ 1. We show that the location of this caustic is always outside of the tidal disruption radius of the star and the compression of the gas near the caustic is at most mildly supersonic, which results in an adiabatic increase in the gas density above the tidal density of the black hole. As such, this in-plane pancake revitalizes the influence of self-gravity even for large β, in agreement with recent simulations. This finding suggests that for all TDEs in which the star is fully disrupted, self-gravity is revived post-pericenter, keeps the stream of debris narrowly confined in its transverse directions, and renders the debris prone to gravitational instability.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020. The American Astronomical Society. This is an author produced version of an article published in Astrophysical Journal Letters. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Nov 2023 11:09 |
Last Modified: | 03 Nov 2023 18:02 |
Status: | Published |
Publisher: | American Astronomical Society |
Identification Number: | 10.3847/2041-8213/abb2ad |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:204843 |