The Instantaneous Convective-Radiative Fingerprint on Mass Ejection in a Red Supergiant Binary: A 3D Morphological and Statistical Analysis

Abstract: Understanding mass transfer in Red Supergiant (RSG) binaries requires detailed, instantaneous 3D insights into the complex interplay of stellar convection and radiation. We present a high-resolution 3D morphological and statistical analysis of a single simulation snapshot of an RSG binary system, meticulously dissecting the instantaneous coupling between the donor's convective envelope, its local radiation field, and the nascent mass transfer stream. Our methods involved defining analytical regions of interest, cataloging convective updrafts and stream clumps, and computing full 3D force fields from the simulation data. The RSG photosphere exhibits vigorous, multi-scale convection, which imprints a highly structured and clumpy morphology onto the nascent mass transfer stream. Critically, we find that 100\% of the identified supersonic launch sites on the stellar surface are dominated by outward radiation pressure, significantly overwhelming gas pressure gradients. Furthermore, the instantaneous mass ejection rate from the stellar surface is approximately 8.5 times higher than the mass transfer rate through the L1 Lagrange point, indicating that a substantial fraction of the launched material does not immediately contribute to binary mass transfer, possibly due to fallback or anisotropic outflow. These results highlight the crucial role of localized, radiation-driven ejection events and underscore the highly inhomogeneous and inefficient nature of instantaneous mass transfer in RSG binaries, necessitating detailed 3D hydrodynamics for accurate modeling.

Subjects:	astro-ph.CO; cs.LG
Cite as:	PX:2508.00017