Interacting compact binaries: modeling mass transfer in eccentric systems

TL;DR

This paper models episodic mass transfer in eccentric white dwarf-neutron star binaries, predicts their orbital properties, and introduces a new SPH formalism for simulating such systems.

Contribution

It presents a novel model for mass transfer in eccentric WD-NS binaries and introduces the oil-on-water SPH formalism for their simulation.

Findings

Predicted orbital properties of WD-NS binaries similar to J1141+6545.

Showed episodic mass transfer occurs in these systems.

Developed a new SPH method for modeling mass transfer.

Abstract

We discuss mass transfer in eccentric binaries containing a white dwarf and a neutron star (WD--NS binaries). We show that such binaries are produced from field binaries following a series of mass transfer episodes that allow the white dwarf to form before the neutron star. We predict the orbital properties of binaries similar to the observed WD--NS binary J1141+6545, and show that they will undergo episodic mass transfer from the white dwarf to the neutron star. Furthermore, we describe oil-on-water, a two-phase SPH formalism that we have developed in order to model mass transfer in such binaries.