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

We report European Very Long Baseline Interferometry Network (EVN) radiocontinuum observations of ASASSN-14li, one of the best studied tidal disruptionevents (TDEs) to date. At 1.7 GHz with ~12x6mas resolution, the emission isunresolved. At 5.0 GHz with ~3x2mas resolution, the radio emission shows anextended structure that can be modeled with two components: a core-likecomponent and a fainter, possibly elongated source 4.3mas (~2pc) away. Ourobservations are not conclusive as to the nature of the components, but threescenarios are discussed. One possibility is a core-jet/outflow morphology, thusmaking of ASASSN-14li the first TDE jet/outflow directly imaged. For this case,the projected separation between the two components can only be explained bysuperluminal motion, rather than the lower velocities inferred fromlow-resolution radio observations. However, typical fast moving jets havebrightness temperatures ~5 orders of magnitude higher than we find, thus makingthis scenario less likely. The second possibility is that we are imaging anon-relativistic jet from past AGN/TDE activity. In this case a past TDE ispreferred given that the spatial extension and radio luminosity of theelongated component are consistent with the theoretical predictions for a TDEoutflow. Alternatively, the two sources could indicate the presence of a binaryblack hole, which would then naturally explain the enhanced TDE rates ofpost-starburst galaxies. Future EVN observations will help us to distinguishbetween these scenarios.

The TDE ASASSN-14li and its host resolved at parsec scales with the EVN