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

Hot subdwarf-B (sdB) stars in long-period binaries are found to be oneccentric orbits, even though current binary-evolution theory predicts theseobjects to be circularised before the onset of Roche-lobe overflow (RLOF). Toincrease our understanding of binary interaction processes during the RLOFphase, we started a long term observing campaign to study wide sdB binaries. Inthis article we present a composite-binary-sdB sample, and the results of thespectral analysis of 9 such systems. The grid search in stellar parameters(GSSP) code is used to derive atmospheric parameters for the cool companions.To cross-check our results and also characterize the hot subdwarfs we used theindependent XTgrid code, which employs Tlusty non-local thermodynamicequilibrium models to derive atmospheric parameters for the sdB component andPhoenix synthetic spectra for the cool companions. The independent GSSP andXTgrid codes are found to show good agreement for three test systems that haveatmospheric parameters available in the literature. Based on the rotationalvelocity of the companions, an estimate for the mass accreted during the RLOFphase and the miminum duration of that phase is made. It is found that the masstransfer to the companion is minimal during the subdwarf formation.

Composite hot-subdwarf binaries -- I. The spectroscopically confirmed sdB sample