SCYON Abstract

Received on February 27 2007

Towards absolute scales of radii and masses of open clusters

AuthorsA.E. Piskunov (1,2,3), E. Schilbach (1), N.V. Kharchenko (1,3,4), S. Röser (1), and R.-D. Scholz (3)
Affiliation
(1) Astronomisches Rechen-Institut, Mönchhofstrasse 12-14, D-69120 Heidelberg, Germany (email: apiskunov@ari.uni-heidelberg.de, elena@ari.uni-heidelberg.de, nkhar@ari.uni-heidelberg.de, roeser@ari.uni-heidelberg.de)
(2) Institute of Astronomy of the Russian Acad. Sci., 48 Pyatnitskaya Str., 109017 Moscow, Russia (email: piskunov@inasan.rssi.ru)
(3) Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany (email: apiskunov@aip.de, nkharchenko@aip.de, rdscholz@aip.de)
(4) Main Astronomical Observatory, 27 Academica Zabolotnogo Str., 03680 Kiev, Ukraine (email: nkhar@mao.kiev.ua)
Accepted byAstronomy & Astrophysics
Contact
URLhttp://www.arxiv.org/abs/astro-ph/0702517
Links

Abstract

In this paper we derive tidal radii and masses of open clusters in the nearest kiloparsecs around the Sun. For each cluster, the mass is estimated from tidal radii determined from a fitting of three-parametric King's profiles to the observed integrated density distribution. Different samples of members are investigated. For 236 open clusters, all contained in the catalogue ASCC, we obtain core and tidal radii, as well as tidal masses. The distributions of the core and tidal radii peak at about 1.5pc and 7 - 10pc, 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(sun), and for about half of the clusters, the masses were obtained with a relative error better than 50%.