Bibcode
Walker, Alistair; Bono, Giuseppe; Cassisi, Santi; Monelli, Matteo; Dall'Ora, Massimo; Andreuzzi, Gloria; Stetson, Peter
Referencia bibliográfica
NOAO Proposal ID #2008B-0155
Advertised on:
8
2008
Número de citas
0
Número de citas referidas
0
Descripción
We propose to complete the observations for a project to produce
definitive Color-Magnitude Diagrams (CMDs) for a carefully chosen sample
of galactic globular clusters, using the Mosaic Camera on the Blanco
telescope. The large field size will enable us to efficiently cover to
beyond the published tidal radius for even the larger clusters in our
sample. We will combine with available archival HST photometry for the
dense cluster cores to measure complete star counts for the evolved
populations for each cluster, and where not available, we will provide
accurate main sequence photometry, which will allow quantification of
the binary fraction and any spread due to composition variations. We
will use existing studies of the variable star populations of each
cluster to provide extra constraints on the cluster formation and
evolution scenarios, given the complex behavior that is increasingly
being found for the more massive galactic globular clusters. The
empirical results will be compared with theoretical predictions provided
by pulsational and evolutionary models, in order to check if they can be
reproduced in the framework of canonical stellar theory or, on the
contrary, one has to invoke - at least in the case of the more massive
clusters - non canonical evolutionary scenarios.