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| EPoS Contribution |
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Mass Segregation in Young Stellar Groups
Helen Kirk Harvard - Smithsonian Center for Astrophysics, Cambridge, MA, USA | |
| In nearby star-forming regions, we identify fourteen well-defined young stellar groups typically ranging between 15 to 30 members, with accurate spectral types and with strong spatial concentration according to minimum spanning tree analysis. Of these, thirteen also have measured proper motions. These motions are also consistent with membership. Most groups have a stellar mass range Mmax/Mmin > 20, consistent with random sampling of the IMF. In each group, the most massive stars tend to lie near the central position, which also tends to be the position of greatest mean surface density. This central location of more massive members resembles the mass segregation seen in older clusters with more members. In these young groups, such concentration of massive stars is unlikely to arise dynamically, since the typical member age is at most ~ one crossing time. Instead, their mass segregation seems to arise because their more massive stars form in central positions of high surface density. | |
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| Caption: Left: YSOs identified in the central region of Lupus 3 from Comeron (2008). Right: The minimal spanning tree structure identified in Lupus 3 with our analysis. The blue circles show the YSO positions, with the circle diameter scaling linearly with the YSO mass (from roughly 0.1 to 5 Msol). The red lines denote the minimal spanning tree structure. Several additional YSOs appear in the left panel, corresponding to Comeron's "suspected Lupus 3 members" for which no spectral type or mass estimate is currently available. % Link to a recent paper related to this work: | |
| Collaborators: Phil Myers, HSCfA, USA |
Suggested Session: Herschel, Massive Stars, Molecular Clouds |