Exploring mass transfer mechanisms in symbiotic systems

TL;DR

This paper investigates the dominant mass transfer mechanisms in symbiotic systems, identifying conditions under which wind Roche-lobe overflow or Bondi-Hoyle-Lyttleton accretion prevail, based on a comprehensive parameter space analysis.

Contribution

It introduces a detailed framework for distinguishing mass transfer regimes in symbiotic systems using a broad parameter space exploration.

Findings

Identified the parameter regimes where WRLOF dominates.

Mapped the conditions favoring BHL accretion.

Analyzed 375 parameter combinations across the space.

Abstract

We define two regimes of the parameter space of symbiotic systems based on the dominant mass transfer mechanism. A wide range of white dwarf (WD) mass, donor mass, and donor radius combinations are explored to determine the separation, for each parameter combination, below which wind Roche-lobe overflow (WRLOF) will be the dominant mass transfer mechanism. The underlying concept is the premise that the wind accelerates. If it reaches the Roche-lobe before attaining sufficient velocity to escape, it will be trapped, and gravitationally focused through the inner Lagrangian point towards the accreting WD. However, if the wind succeeds in attaining the required velocity to escape from the donor's Roche-lobe, it will disperse isotropically, and the dominant mass transfer mechanism will be the Bondi-Hoyle-Lyttleton (BHL) prescription in which only a fraction of the wind will be accreted onto the WD. We present, these two regimes of the four dimensional parameter space, covering 375 different parameter combinations.