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

Context: To quantitatively decode the information stored within an observedspectrum, detailed modelling of the physical state and accurate radiativetransfer solution schemes are required. In the analysis of stellar spectra, thenumerical model often needs to account for binary companions and 3D structuresin the stellar envelopes. The enigmatic binary (or multiple) system LB-1constitutes a perfect example of such a complex multi-D problem. Aims: Toimprove our understanding of the LB-1 system, we directly modelled thephase-dependent H-alpha line profiles of this system. To this end, we developeda multi-purpose binary-object spectral-synthesis code in 3D (BOSS-3D). Methods:BOSS-3D calculates synthetic line profiles for a given state of thecircumstellar material. The standard pz-geometry commonly used for single starsis extended by defining individual coordinate systems for each involved objectand by accounting for the appropriate coordinate transformations. The code isthen applied to the LB-1 system, considering two main hypotheses, a binarycontaining a stripped star and Be star, or a B star and a black hole with adisc. Results: Comparing these two scenarios, neither model can reproduce thedetailed phase-dependent shape of the H-alpha line profiles. A satisfactorymatch with the observations, however, is obtained by invoking a disc around theprimary object in addition to the Be-star disc or the black-hole accretiondisc. Conclusions: The developed code can be used to model synthetic lineprofiles for a wide variety of binary systems, ranging from transit spectra ofplanetary atmospheres, to post-asymptotic giant branch binaries includingcircumstellar and circumbinary discs and massive-star binaries with stellarwinds and disc systems. For the LB-1 system, our modelling provides strongevidence that each object in the system contains a disc-like structure.

Binary-object spectral-synthesis in 3D (BOSS-3D) -- Modelling H-alpha emission in the enigmatic multiple system LB-1