H sub(2)O maser emission in the direction of Sagittarius B2: Results of monitoring for 1982-1992

• Published in: Astronomy reports 2004-03, Vol.48 (3), p.171-184
• Main Authors: Lekht, EE, Ramirez Hernandes, O, Tolmachev, A M, Berulis, I I
• Format: Article
• Language: English
• ISSN: 1063-7729; 1562-6881
• DOI: 10.1134/1.1687011

The results of monitoring the water-vapor maser at l=1.35 cm in Sgr B2 are presented. The observations were carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory (Russia) in 1982-1992. A strong flare of the maser radiation associated with Sgr B2(N) was detected in this period. The absolute strength of this flare is comparable to the megamaser emission observed in Orion in 1979-1987. The flare is probably due to a strengthening of the flow of material from the rotating accretion disk, in which are embedded the three ultracompact HII regions K1, K2, and K3. A subsequent excitation of emission features at increasingly higher radial velocities was observed, associated with a gradient of V sub(LSR) along the direction of the outflow. The large width of the lines (>0.86 km/s) could reflect a complex structure for the maser spots, such as a chain or filamentary structure, as has been observed in Orion and S140.