1. Variations in the spectrum and spatial structure of the H2O maser in W75N.
- Author
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Lekht, E. E., Slysh, V. I., and Krasnov, V. V.
- Subjects
- *
ASTRONOMICAL masers , *SPECTRUM analysis , *CIRCUMSTELLAR matter , *STARS , *ASTRONOMY - Abstract
A probable model for the circumstellar envelope associated with the source VLA 2 in W75N has been constructed, based on H2O-maser monitoring toward W75N carried out on the 22-m radio telescope in Pushchino, as well as VLA maps for 1992, 1996, 1998, and 1999. The envelope has a complex hierarchical structure, including individual maser spots, clusters and chains of spots, inhomogeneous filaments, individual arc-shaped layers, and other complicated features. Most widespread are multi-link chains or filaments with sizes of 1–2 AU. This pattern arises due to the complex hierarchical structure of turbulent motions of material on various scales, from microturbulence to large-scale chaotic motions. No expansion of individual layers in the envelope of VLA 2 has been found. The appearance of the layers is due to the passage of MHD waves that excite the maser emission in consecutive shells in the envelope. This process is fairly cyclic, and is related to the flare activity of the star. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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