Gas Flows Within Cavities of Circumbinary Discs in Eccentric Binary Protostellar Systems

Understand

The structure and evolution of gas flows within the cavity of a circumbinary disk (CBD) surrounding the stellar components in eccentric binaries are examined via two-dimensional hydrodynamical simulations.

• The degree to which gas fills the cavity between the circumstellar disks (CSDs) and the CBD is found to be greater for highly eccentric systems, in comparison to low-eccentricity systems, reflecting the spatial extent over which mass enters into the cavity throughout the orbit.
• The pattern of the gas flow in the cavity differs for eccentric binaries from that of binaries in a circular orbit.
• In particular, the former reveals tightly wound gas streams and figure-eight-like structures for systems characterized by eccentricities, $e \ge 0.4$, whereas the latter only reveal relatively loosely bent streams from the CBD to the CSDs.