English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A tidal disruption event (TDE) occurs when a star passes too close to asupermassive black hole and gets torn apart by its gravitational tidal field.After the disruption, the stellar debris form an expanding gaseous stream. Themorphology and evolution of this stream is particularly interesting as itultimately determines the observational properties of the event itself. In thiswork we perform 3D hydrodynamical simulations of the TDE of a star modelled asa polytropic sphere of index {\gamma} = 5/3, and study the gravitationalstability of the resulting gas stream. We provide an analytical solution forthe evolution of the stream in the bound, unbound and marginally bound case,that allows us to describe the stream properties and analyse the time-scales ofthe physical processes involved, applying a formalism developed in starformation context. Our results are that, when fragmentation occurs, it isfueled by the failure of pressure in supporting the gas against itsself-gravity. We also show that a stability criterion that includes also thestream gas pressure proves to be far more accurate than one that only considersthe black hole tidal forces, giving analytical predictions of the timeevolution of the various forces associated to the stream. Our results point outthat fragmentation occurs on timescales longer compared with the observationalwindows of these events and is thus not expected to give rise to significantobservational features.

What causes the fragmentation of debris streams in TDEs?