Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-07-25
Astronomy and Astrophysics
Astrophysics
13 pages, 13 figures; accepted by A&A
Scientific paper
10.1051/0004-6361:200810236
Usually, a loose stellar distribution can be classified as an OB stellar group, an association, or a young open cluster. We make use of comparisons with the typical OB association Vul OB1. In the present paper we discuss the nature of Bochum 1, a typical example of an object affected by the above classification problem.The field-decontaminated CMD of Bochum 1 presents main sequence (MS) and pre-main sequence (PMS) stars. We report two new small angular-size, compact young clusters and one embedded cluster in the area of Bochum 1. Vul OB1 harbours the young open cluster NGC 6823 and the very compact embedded cluster Cr 404. The Vul OB1 association includes the H II region Sh2-86, and its stellar content is younger ($\approx3$ Myr) than that of Bochum 1 ($\approx9$ Myr), which shows no gas emission. Bochum 1 harbours one of the newly found compact clusters as its core. The RDP of Bochum 1 is irregular and cannot be fitted by a King-like profile, which suggests important erosion or dispersion of stars from a primordial cluster. Similarly to Bochum 1, the decontaminated CMD of NGC 6823 presents conspicuous MS and PMS sequences. Taken separately, RDPs of MS and PMS stars follow a King-like profile. The core shows an important excess density of MS stars that mimics the profile of a post-core collapse cluster. At such young age, it can be explained by an excess of stars formed in the prominent core. The present study suggests that Bochum 1 is a star cluster fossil remain that might be dynamically evolving into an OB association. Bochum 1 can be a missing link connecting early star cluster dissolution with the formation of low-mass OB associations.
Bica Eduardo
Bonatto Charles
Dutra Carlos M.
No associations
LandOfFree
Investigating the borderline between a young star cluster and a small stellar association: a test case with Bochum1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Investigating the borderline between a young star cluster and a small stellar association: a test case with Bochum1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Investigating the borderline between a young star cluster and a small stellar association: a test case with Bochum1 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-325742