Poster abstract details
Kinematic age determinations of Planetary Nebula central stars
Abstract
Central stars of planetary nebulae (CSPN) have a relatively large mass interval, so that it is expected that these stars also have different ages, typically above 1 Gyr. Apart from the properties of the CSPN themselves, the problem of age determination is also important in the context of the chemical evolution of the Galaxy, for instance in the understanding of the time variation of chemical abundance gradients. However, the accurate determination of CSPN ages is a complex problem, and there are no unique
and reliable methods. In this work, we estimate the ages of a sample of CSPN on the basis of some correlations between their kinematic properties and the expected ages. According to these correlations, the observed dispersions in the U, V, W velocities are uniquely defined by the stellar ages. Two samples were chosen, containing approximatetly 200 and 800 nebulae, respectively, for which accurate radial velocities are available in the literature. The adopted correlations were derived from the recent Geneva-Copenhagen survey of galactic stars. Preliminary results suggest the most CSPN in the galactic disk have ages under 3 Gyr. These results are also compared with some recent age distributions based on independent correlations involving the nebular chemical abundances. (FAPESP/CNPq)
and reliable methods. In this work, we estimate the ages of a sample of CSPN on the basis of some correlations between their kinematic properties and the expected ages. According to these correlations, the observed dispersions in the U, V, W velocities are uniquely defined by the stellar ages. Two samples were chosen, containing approximatetly 200 and 800 nebulae, respectively, for which accurate radial velocities are available in the literature. The adopted correlations were derived from the recent Geneva-Copenhagen survey of galactic stars. Preliminary results suggest the most CSPN in the galactic disk have ages under 3 Gyr. These results are also compared with some recent age distributions based on independent correlations involving the nebular chemical abundances. (FAPESP/CNPq)