Massive star formation in the W49 giant molecular cloud: Implications for the formation of massive star clusters
- Author(s)
- N. L. Homeier, J. Alves
- Abstract
We present results from JHKs imaging of the densest region of the W49 molecular cloud. In a recent paper (\cite{AH03}, ApJL, 589, L45), we reported the detection of (previously unknown) massive stellar clusters in the well-known giant radio HII region W49A, and here we continue our analysis. We use the extensive line-of-sight extinction to isolate a population of objects associated with W49A. We constrain the slope of the stellar luminosity function by constructing an extinction-limited luminosity function, and use this to obtain a mass function. We find no evidence for a top-heavy MF, and the slope of the derived mass function is -1.6 ± 0.3. We identify candidate massive stars from our color-magnitude diagram, and we use these to estimate the current total stellar mass of 5-7×104 M⊙ in the region of the W49 molecular cloud covered by our survey. Candidate ionizing stars for several ultra-compact HII regions are detected, with many having multipe candidate sources. On the global molecular cloud scale in W49, massive star formation apparently did not proceed in a single concentrated burst, but in small groups, or subclusters. This may be an essential physical description for star formation in what will later be termed a ``massive star cluster''.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- European Southern Observatory (Germany), Johns Hopkins University
- Journal
- Astronomy & Astrophysics
- Volume
- 430
- Pages
- 481-489
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361:20040447
- Publication date
- 02-2005
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/45c74485-fda1-4dd3-bf62-dd78d99f8d17