P. Barmby et al. 2009 The Astronomical Journal 138 1667 doi:10.1088/0004-6256/138/6/1667
P. Barmby1, S. Perina2,3, M. Bellazzini2,3, J. G. Cohen4, P. W. Hodge5, J. P. Huchra6, M. Kissler-Patig7, T. H. Puzia8 and J. Strader6,9
Show affiliationsSurface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fitted to two types of models to determine the clusters' structural properties. The clusters are primarily young (~108 yr) and massive (~104.5 M ☉), with median half-light radius 7 pc and dissolution times of a few Gyr. The properties of the M31 clusters are comparable to those of clusters of similar age in the Magellanic Clouds. Simulated star clusters are used to derive a conversion from statistical measures of cluster size to half-light radius so that the extragalactic clusters can be compared to young massive clusters in the Milky Way. All three sets of star clusters fall approximately on the same age-size relation. The young M31 clusters are expected to dissolve within a few Gyr and will not survive to become old, globular clusters. However, they do appear to follow the same fundamental plane (FP) relations as old clusters; if confirmed with velocity dispersion measurements, this would be a strong indication that the star cluster FP reflects universal cluster formation conditions.
galaxies: individual (Messier: Number M31); galaxies: star clusters; globular clusters: general
Issue 6 (2009 December)
Received 2009 July 31, accepted for publication 2009 September 15
Published 2009 October 30
P. Barmby et al. 2009 The Astronomical Journal 138 1667
Feng Yang et al 2009 J. Phys. D: Appl. Phys. 42 072004
S. Kafka et al. 2007 The Astronomical Journal 133 1645
Z. Peeters et al 2003 ApJ 593 L129
L. Covi et al JHEP11(2009)003
A Werber and H Zappe 2006 J. Opt. A: Pure Appl. Opt. 8 S313
J C Reichert et al 2009 Biomed. Mater. 4 065001
C M Illingworth and A T Barker 1980 Clin. Phys. Physiol. Meas. 1 87
Luzi Bergamin et al JHEP11(2004)021
Huimin Xie 1996 Nonlinearity 9 1469