Constraining white-dwarf kicks in globular clusters : II. Observational Significance

TL;DR

This paper investigates how asymmetric stellar winds can impart kicks to white dwarfs in globular clusters, affecting their spatial and kinematic distributions, with implications for understanding stellar evolution and cluster dynamics.

Contribution

It provides observational evidence and analysis of white dwarf kicks, highlighting their impact on spatial distribution and orbital eccentricities in globular clusters.

Findings

Young white dwarfs are less centrally concentrated than their progenitors.

White dwarfs exhibit increased orbital eccentricities due to kicks.

Kinematic signatures are detectable through proper motion position angles.

Abstract

If the winds of an asymptotic-giant-branch stars are sufficiently strong are slightly asymmetric, they can alter the star's trajectory through a globular cluster; therefore, if these winds are asymmetric, one would expect young white dwarfs to be less radially concentrated than either their progenitors or older white dwarfs in globular clusters. This latter effect has recently been observed. Additionally the young white dwarfs should have larger typical velocities than their progenitors. After phase mixing this latter effect is vastly diminished relative to the changes in the spatial distribution of young white dwarfs with kicks, so it is more difficult to detect than the change in the spatial distribution. The most powerful kinematic signature is the change in the eccentricity of the orbits that is revealed through the distribution of the position angles of proper motion.