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

Mass transfer in cataclysmic variables (CVs) is usually considered to becaused by angular momentum loss (AML) driven by magnetic braking andgravitational radiation (GR) above the period gap, and solely by GR below theperiod gap. The best-fit revised model of CV evolution recently by\citet{kbp11}, however, indicates that AML rate below the period gap is$2.47(\pm 0.22)$ times the GR rate, suggesting the existence of some other AMLmechanisms. We consider several kinds of consequential AML mechanisms ofteninvoked in the literature: isotropic wind from the accreting white dwarfs,outflows from the Langrangian points, and the formation of a circumbinary disk.We found that neither isotropic wind from the white dwarf nor outflow from the$L_1$ point can explain the extra AML rate, while ouflow from the $L_2$ pointor a circumbinary disk can effectively extract the angular momentum providedthat $\sim (15-45)%$ of the transferred mass is lost from the binary. A morepromising mechanism is a circumbinary disk exerting gravitational torque on thebinary. In this case the mass loss fraction can be as low as $\lesssim10^{-3}$.

Angular Momentum Loss Mechanisms in Cataclysmic Variables below the Period Gap