Towards absolute scales for the radii and masses of open clusters
Abstract
Aims: In this paper we derive tidal radii and masses of open clusters in the nearest kiloparsecs around the Sun.
Methods: For each cluster, the mass is estimated from tidal radii determined from a fitting of three-parameter King profiles to the observed integrated density distribution. Different samples of members are investigated.
Results: For 236 open clusters, all contained in the catalogue ASCC-2.5, we obtain core and tidal radii, as well as tidal masses. The distributions of the core and tidal radii peak at about 1.5 pc and 7-10 pc, respectively. A typical relative error of the core radius lies between 15% and 50%, whereas, for the majority of clusters, the tidal radius was determined with a relative accuracy better than 20%. Most of the clusters have tidal masses between 50 and 1000 m_⊙, and for about half of the clusters, the masses were obtained with a relative error better than 50%.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 2007
- DOI:
- 10.1051/0004-6361:20077073
- arXiv:
- arXiv:astro-ph/0702517
- Bibcode:
- 2007A&A...468..151P
- Keywords:
-
- Galaxy: open clusters and associations: general;
- solar neighbourhood;
- Galaxy: stellar content;
- Astrophysics
- E-Print:
- 11 pages, 7 figures, accepted for publication in Astronomy &