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| EPoS Contribution |
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Dynamical, accretion, and photoevaporative truncation of disks living in dense clusters
Adam Ginsburg U Florida, Gainesville, US | |
| Many, probably most, stars formed in dense clusters. Such clusters are sites of more frequent close encounters and dynamical interactions. The poster case for a dynamical decay resulting in disk truncation is the high-mass (15 Msun) protostar Orion Source I. The cluster surrounding Source I, embedded deep within the Orion Molecular Cloud (OMC), is the densest in the local neighborhood, even denser than the Orion Nebula Cluster (ONC). More than half of the X-ray-detected young sources within the OMC have disks, and the disks are more massive than in other well-surveyed nearby regions, including the broader Orion cloud. However, the disks are smaller in both the OMC and ONC than those in other samples. This difference points toward physical mechanisms. Frequent dynamical interaction with other stars is not likely to explain the whole population at the observed density, but it plays some role. Instead, accretion-driven truncation, in which the disks are moving with respect to the surrounding cloud and sweeping up low-angular-momentum material, describes how small and massive disks are maintained. The ONC disks, which are not shielded by the dense OMC, are likelier to be truncated by external photoevaporation. | |
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| Caption: (top left) The Orion BN/KL region shown in H2 (orange), FeII (blue), and 2-micron continuum (white). Small circles indicate detected disks in ALMA long-baseline data. Blue dashed circles show the field-of-view of ALMA at 3mm, 1.4mm, and 0.85mm. (top right) Zoom-in figure showing a subset of the 127 detected disks, of which 72 are resolved. The red labels show newly-detected sources. (bottom) The locations of optically-detected (left) and non-detected (right) disks are shown as blue stars. The background colorscale shows the local density; the median OMC (right) density is 1.6×105 stars per cubic parsec, while the ONC's (left) density is 6×104. Both of these estimates are higher than historical estimates that were limited to stars detected in the optical or near-infrared. | |
| Collaborators: J. Otter J. Bally N. Ballering C. Goddi D. Plambeck M. Wright J. Eisner |
Key publication
Suggested Session: Cores2Disks |