Newly Identified Star Clusters in M33: Space-Based Survey

Abstract

AbstractHiltner (1960) present photometry of 23 M33 cluster candidates and 23 M31 globular clusters using photographic plates at the 2.5 m Mt. Wilson Telescope. Since this early study, it was established that, in general, clusters in M33 are bluer and fainter than those in M31. There have been a number of M33 cluster catalogs published since this pioneer work. The most comprehensive catalog of extended objects in M33 was compiled by Christian and Schommer (1982, 1988). They present a catalog of 250 nonstellar objects including photometry of 106 star cluster candidates. More recently, Mochejska et al. (1998) detect 51 star clusters candidates, of which 32 were not previously cataloged. With the arrival of the HST, studies of the M33 star clusters have rapidly increased (Bedin et al. 2005; Chandar et al. 1999a, b, c, 2001, 2002). Ma et al. (2001, 2002a, b, c, 2004a, b) obtained ages of M33 star clusters using spectral energy distributions in 13 intermediate filters of the Beijing-Arizona-Taiwan-Connecticut (BATC) photometric system. The reader is referred to the work of Sarajedini and Mancone (2007) (hereafter SM), which merged all of the modern catalogs compiled before 2007, for a summary of the properties of all of these catalogs. Even the results of Park and Lee (2007), which appeared after the publication of SM have been incorporated into the web-based version of the SM catalog.KeywordsCluster CenterHubble Space TelescopeStar ClusterCluster CandidateStellar ClusterThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.