English

Star Cluster Candidates in M81

Cosmology and Nongalactic Astrophysics 2015-05-14 v3

Abstract

We present a catalog of extended objects in the vicinity of M81 based a set of 24 Hubble Space Telescope Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) F814W (I-band) images. We have found 233 good globular cluster candidates; 92 candidate HII regions, OB associations, or diffuse open clusters; 489 probable background galaxies; and 1719 unclassified objects. We have color data from ground-based g- and r-band MMT Megacam images for 79 galaxies, 125 globular cluster candidates, 7 HII regions, and 184 unclassified objects. The color-color diagram of globular cluster candidates shows that most fall into the range 0.25 < g-r < 1.25 and 0.5 < r-I < 1.25, similar to the color range of Milky Way globular clusters. Unclassified objects are often blue, suggesting that many of them are likely to be HII regions and open clusters, although a few galaxies and globular clusters may be among them.

Keywords

Cite

@article{arxiv.0908.4091,
  title  = {Star Cluster Candidates in M81},
  author = {J. B. Nantais and J. P. Huchra and B. McLeod and J. Strader and J. P. Brodie},
  journal= {arXiv preprint arXiv:0908.4091},
  year   = {2015}
}

Comments

35 pages, 11 figures, submitted to AJ

R2 v1 2026-06-21T13:39:45.252Z