EMBEDDED YOUNG STELLAR OBJECT CANDIDATES IN THE ACTIVE STAR-FORMING COMPLEX W51: MASS FUNCTION AND SPATIAL DISTRIBUTION
- International Center for Astrophysics, Korea Astronomy and Space Science Institute, Hwaam 61-1, Yuseong, Daejeon 305-348 (Korea, Republic of)
- Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
We present 737 candidate young stellar objects (YSOs) near the W51 giant molecular cloud over an area of 1.{sup 0}25 x 1.{sup 0}00 selected from Spitzer Space Telescope data. We use spectral energy distribution fits to identify YSOs and distinguish them from main-sequence (MS) or red giant stars, asymptotic giant branch stars, and background galaxies. Based on extinction of each YSO, we separate a total of 437 YSOs associated with the W51 region from the possible foreground sources. We identify 69 highly embedded Stage 0/I candidate YSOs in our field with masses >5 M{sub sun} (corresponding to mid- to early-B MS spectral types), 46 of which are located in the central active star-forming regions of W51A and W51B. From the YSOs associated with W51, we find evidence for mass segregation showing that the most massive YSOs are concentrated on the W51 H II region complex. We find a variation in the spatial distribution of the mass function (MF) of YSOs in the mass range between 5 M{sub sun} and 18 M{sub sun}. The derived slopes of the MF are -1.26 and -2.36 in the active star-forming region and the outer region, respectively. The variation of the MF for YSOs embedded in the molecular cloud implies that the distribution of stellar masses in clusters depends on the local conditions in the parent molecular cloud.
- OSTI ID:
- 21378236
- Journal Information:
- Astrophysical Journal, Vol. 706, Issue 1; Other Information: DOI: 10.1088/0004-637X/706/1/83; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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