The H 2 O super maser emission of Orion KL accretion disk, bipolar outflow, shell

• Published in: Proceedings of the International Astronomical Union 2006-08, Vol.2 (S237), p.446-446
• Main Authors: Matveyenko, Leonid I., Demichev, V. A., Sivakon, S. S., Diamond, P. D., Graham, D. A.
• Format: Article
• Language: English
• ISSN: 1743-9213; 1743-9221
• DOI: 10.1017/S1743921307002347

The H 2 O super maser outbursts were observed in Orion KL in active periods 1979-1987 ( F ≤ 8 MJy) and 1998-1999 ( F ≤ 4 MJy). The line velocity was V LSR = 7.65 km/s and line width Δ V ~ 0.5 km/s. The emission was linear polarized m ≤ 75%. We studied structure of H 2 O super maser region with VLBI angular resolution 0.1 mas or 0.05 AU. The emission was determined by high organized structure: a chain of bright ( T b ~ 10 16 K ) compact components (~ 0.05 AU), which are distributed along thin S-form structure 27× 0.3 AU, T b ~ 10 11 K, Fig. 1. The brightest components have velocities V ~ 7.65 km/s. The components correspond to tangential direction of the rings, velocities of which are V ~ Ω R and rotation period is ~180 yrs. The highly collimated bipolar outflow 9x0.7 AU and comet-like bullets were observed in the quiescent period 1995 (F= 1 kJy) and second activity period 1998-1999. The central compact (0.05 AU) bright ( T b ~ 10 16 K ) source is ejector of bipolar outflow, which surrounded by a torus. Compact bright features are located in the outflow, which velocities are V ~ 10 km/s in the beginning of activity, and V ~ 3 km/s in the end. The helix structure of outflow is determined by precession with period T ~ 10 yrs. The bullets were ejected in the first period activity. Extraordinary changing of the polarization position angle dX / dV ~ 23 o /km/s is determined by nozzle emission.