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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The role of recombination during a common-envelope event has been longdebated. Many studies have argued that much of hydrogen recombination energy,which is radiated in relatively cool and optically-thin layers, might notthermalise in the envelope. On the other hand, helium recombination contains30% of the total recombination energy, and occurs much deeper in the stellarenvelope. We investigate the distinct roles played by hydrogen and heliumrecombination in a common-envelope interaction experienced by a 12 solar massred supergiant donor. We perform adiabatic, 3D hydrodynamical simulations that(i) include hydrogen, helium, and molecular hydrogen recombination, (ii)include hydrogen and helium recombination, (iii) include only heliumrecombination, and (iv) do not include recombination energy. By comparing thesesimulations, we find that the addition of helium recombination energy aloneejects 30% more envelope mass, and leads to a 16% larger post-plunge-inseparation. Under the adiabatic assumption, adding hydrogen recombinationenergy increases the amount of ejected mass by a further 40%, possiblyunbinding the entire envelope, but does not affect the post-plunge separation.Most of the ejecta becomes unbound at relatively high (>70%) degrees ofhydrogen ionisation, where the hydrogen recombination energy is likely toexpand the envelope instead of being radiated away.

Common envelopes in massive stars II: The distinct roles of hydrogen and helium recombination