The structure accompanying young star formation
Abstract
We studied the structure of the H2O super maser region in Orion with VLBI angular resolution of 0.1 mas or 0.05 AU. The maser emission (F ∼ 8 MJy) was determined by highly organized structure: accretion disk, bipolar outflow, torus and surrounding shell. The accretion disk, divided into protoplanetary rings, is viewed edge-on. The disk rotates as a rigid body with velocities V ∼ ΩR and the rotation period is ∼ 170 yrs. The highly collimated bipolar outflow has a size of 9×0.7 AU, a velocity of ∼ 10 km/s. In the center a bright compact (≤0.05 AU) source - ejector is located, surrounded by a torus 0.6 AU in diameter. The outflow has a helix structure, which is determined by precession with a period of T ∼ 10 yrs. Comet-like bullets were observed on distances up to 80 AU.
- Publication:
-
Star-Disk Interaction in Young Stars
- Pub Date:
- May 2007
- DOI:
- Bibcode:
- 2007IAUS..243..215D
- Keywords:
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- Jets;
- bipolar outflows;
- accretion disk;
- maser