Evolution of LMXBs under Different Magnetic Braking Prescriptions

TL;DR

This study compares five magnetic braking laws to understand their impact on low-mass X-ray binary evolution, finding that the τ-boosted MB law aligns best with observed data.

Contribution

It introduces a comprehensive comparison of different magnetic braking prescriptions using binary evolution and population synthesis to identify the most realistic model.

Findings

τ-boosted MB law best matches observations

Different MB laws produce distinct LMXB evolutionary outcomes

The study helps constrain magnetic braking physics in binary systems

Abstract

Magnetic braking (MB) likely plays a vital role in the evolution of low-mass X-ray binaries (LMXBs). However, it is still uncertain about the physics of MB, and there are various proposed scenarios for MB in the literature. To examine and discriminate the efficiency of MB, we investigate the LMXB evolution with five proposed MB laws. Combining detailed binary evolution calculation with binary population synthesis, we obtain the expected properties of LMXBs and their descendants binary millisecond pulsars. We then discuss the strength and weakness of each MB law by comparing the calculated results with observations. We conclude that the $\tau$-boosted MB law seems to best match the observational characteristics.