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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Disc winds are a common feature in accreting astrophysical systems on allscales. In active galactic nuclei (AGN) and accreting white dwarfs (AWDs),specifically, radiation pressure mediated by spectral lines is a promisingmechanism for driving these outflows. Previous hydrodynamical simulations havelargely supported this idea, but relied on highly approximate treatments ofionization and radiative transfer. Given the sensitivity of line driving to theionization state and radiation field in the outflow, here we present a newmethod for carrying out 2.5D radiation-hydrodynamic simulations that takes fullaccount of the frequency-dependent radiative transfer through the wind, thecorresponding ionization state and the resulting radiative accelerations.Applying our method to AWDs, we find that it is much harder to drive a powerfulline-driven outflow when the interaction between matter and radiation istreated self-consistently. This conclusion is robust to changes in the adoptedsystem parameters. The fundamental difficulty is that discs luminous enough todrive such a wind are also hot enough to over-ionize it. As a result, themass-loss rates in our simulations are much lower than those found in earlier,more approximate calculations. We also show that the ultraviolet spectraproduced by our simulations do not match those observed in AWDs. We concludethat, unless the over-ionization problem can be mitigated (e.g. by sub-gridclumping or a softer-than-expected radiation field), line driving may not be apromising mechanism for powering the outflows from AWDs. These conclusions arelikely to have significant implications for disc winds in AGN also.

State-of-the-art simulations of line-driven accretion disc winds: realistic radiation-hydrodynamics leads to weaker outflows