A new method for calculating the convergent point of a moving group
Idioma
en
Article de revue
Este ítem está publicado en
Astronomy and Astrophysics - A&A. 2012, vol. 538, p. A23
EDP Sciences
Resumen en inglés
Context: Convergent point (CP) search methods are important tools for studying the kinematic properties of open clusters and young associations whose members share the same spatial motion. Aims: We present a new CP search ...Leer más >
Context: Convergent point (CP) search methods are important tools for studying the kinematic properties of open clusters and young associations whose members share the same spatial motion. Aims: We present a new CP search strategy based on proper motion data. We test the new algorithm on synthetic data and compare it with previous versions of the CP search method. As an illustration and validation of the new method we also present an application to the Hyades open cluster and a comparison with independent results. Methods: The new algorithm rests on the idea of representing the stellar proper motions by great circles over the celestial sphere and visualizing their intersections as the CP of the moving group. The new strategy combines a maximum-likelihood analysis for simultaneously determining the CP and selecting the most likely group members and a minimization procedure that returns a refined CP position and its uncertainties. The method allows one to correct for internal motions within the group and takes into account that the stars in the group lie at different distances. Results: Based on Monte Carlo simulations, we find that the new CP search method in many cases returns a more precise solution than its previous versions. The new method is able to find and eliminate more field stars in the sample and is not biased towards distant stars. The CP solution for the Hyades open cluster is in excellent agreement with previous determinations.< Leer menos
Palabras clave en inglés
methods: statistical
open clusters and associations: general
astrometry
methods: analytical
proper motions
open clusters and associations: individual: Hyades
Orígen
Importado de HalCentros de investigación