تقرير
Diffraction-limited Visible Light Images of Orion Trapezium Cluster With the Magellan Adaptive Secondary AO System (MagAO)
| العنوان: | Diffraction-limited Visible Light Images of Orion Trapezium Cluster With the Magellan Adaptive Secondary AO System (MagAO) |
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| المؤلفون: | Close, L. M., Males, J. R., Morzinski, K., Kopon, D., Follette, K., Rodigas, T. J., Hinz, P., Wu, Y-L., Puglisi, A., Esposito, S., Riccardi, A., Pinna, E., Xompero, M., Briguglio, R., Uomoto, A., Hare, T. |
| سنة النشر: | 2013 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high spatial resolution observations in "visible light" with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5-0.7") we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63 micron) images are slightly coarser at FWHM=23-29 mas (Strehl ~28%) with bright (R<9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~1 Myr) Orion Trapezium Theta 1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary Theta 1 Ori C1/C2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~0.6-5 mas accuracy. We now are sensitive to relative proper motions of just ~0.2 mas/yr (~0.4 km/s at 414 pc) - this is a ~2-10x improvement in orbital velocity accuracy compared to previous efforts. For the first time, we see clear motion of the barycenter of Theta 1 Ori B2/B3 about Theta 1 Ori B1. All five members of the Theta 1 Ori B system appear likely a gravitationally bound "mini-cluster", but we find that not all the orbits can be both circular and co-planar. The lowest mass member of the Theta 1 Ori B system (B4; mass ~0.2 Msun) has a very clearly detected motion (at 4.1+/-1.3 km/s; correlation=99.9%) w.r.t B1 and will likely be ejected in the future. This "ejection" process of the lowest mass member of a "mini-cluster" could play a major role in the formation of low mass stars and brown dwarfs.(slightly abridged abstract) Comment: 35 pages, 17 figures, to appear in the Sept. 10, 2013 issue of ApJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/0004-637X/774/2/94 |
| URL الوصول: | http://arxiv.org/abs/1308.4155 |
| رقم الأكسشن: | edsarx.1308.4155 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/0004-637X/774/2/94 |
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