Mass Segregation in the Globular Cluster Palomar 5 and its Tidal Tails
Abstract
We present the stellar main sequence luminosity function (LF) of the disrupted, low-mass, low-concentration globular cluster Palomar 5 and its well-defined tidal tails, which emanate from the cluster as a result of its tidal interaction with the Milky Way. The results of our deep (B ~ 24.5) wide-field photometry unequivocally indicate that preferentially fainter stars were removed from the cluster so that the LF of the cluster's main body exhibits a significant degree of flattening compared to other globular clusters. There is clear evidence of mass segregation, which is reflected in a radial variation of the LFs. The LF of the tidal tails is distinctly enhanced with faint, low-mass stars. Pal 5 exhibits a binary main sequence, and we estimate a photometric binary frequency of roughly 10%. Also the binaries show evidence of mass segregation with more massive binary systems being more strongly concentrated toward the cluster center.
Cite
@article{arxiv.astro-ph/0408208,
title = {Mass Segregation in the Globular Cluster Palomar 5 and its Tidal Tails},
author = {A. Koch and E. K. Grebel and M. Odenkirchen and D. Martinez-Delgado and J. A. R. Caldwell},
journal= {arXiv preprint arXiv:astro-ph/0408208},
year = {2009}
}
Comments
14 pages, 12 figures, accepted for publication in the Astronomical Journal