Kinematic ages of central stars of planetary nebulae

TL;DR

This paper estimates the ages of central stars in planetary nebulae using their kinematic properties, revealing most are younger than 5 billion years with a peak around 1 to 3 billion years.

Contribution

It introduces two novel kinematic methods to determine the age distribution of planetary nebulae central stars, validated on two Galactic samples.

Findings

Most central stars are younger than 5 Gyr.

Age distribution peaks at 1-3 Gyr.

Methods yield consistent results across samples.

Abstract

The age distribution of the central stars of planetary nebulae (CSPN) is estimated using two methods based on their kinematic properties. First, the expected rotation velocities of the nebulae at their Galactocentric distances are compared with the predicted values for the rotation curve, and the differences are attributed to the different ages of the evolved stars. Adopting the relation between the ages and the velocity dispersions determined by the Geneva-Copenhagen survey, the age distribution can be derived. Second, the U, V, W, velocity components of the stars are determined, and the corresponding age-velocity dispersion relations are used to infer the age distribution. These methods have been applied to two samples of PN in the Galaxy. The results are similar for both samples, and show that the age distribution of the PN central stars concentrates in ages lower than 5 Gyr, peaking at about 1 to 3 Gyr.