Periodic variability of the mainline hydroxyl masers in G9.62+0.20E

Abstract

We present the results of a monitoring campaign using the KAT-7 and HartRAO 26m telescopes, of hydroxyl, methanol and water vapour masers associated with the high-mass star forming region G9.62+0.20E. Periodic flaring of the main line hydroxyl masers were found, similar to that seen in the 6.7 and 12.2 GHz methanol masers. The 1667 MHz flares are characterized by a rapid decrease in flux density which is coincident with the start of the 12.2 GHz methanol maser flare. The decrease in the OH maser flux density is followed by a slow increase till a maximum is reached after which the maser decays to its pre-flare level. A possible interpretation of the rapid decrease in the maser flux density is presented. Considering the projected separation between the periodic methanol and OH masers, we conclude that the periodic 12.2 methanol masing region is located about 1600 AU deeper into the molecular envelope compared to the location of the periodic OH masers. A single water maser flare was also detected which seems not to be associated with the same event that gives rise to the periodic methanol and OH maser flares.

arXiv comment8 pages, 11 figures

References in corpus (18)

• Full-Polarization Observations of OH Masers in Massive Star-Forming Regions: I. Data
• Quasi-Periodic Formaldehyde Maser Flares in the Massive Protostellar Object IRAS18566+0408
• On the Class II Methanol Maser Periodic Variability due to the Rotating Spiral Shocks in the Gaps of Disks Around Young Binary Stars
• Periodic class II methanol masers in G9.62+0.20E
• On the methanol masers in G9.62+0.20E and G188.95+0.89
• Periodicity in Class II methanol masers in high mass star forming regions
• Short-period variability in the Class II methanol maser source G12.89+0.49 (IRAS 18089-1732)
• VLBA imaging of a periodic 12.2 GHz methanol maser flare in G9.62+0.20E
• Discovery of periodic and alternating flares of the methanol and water masers in G107.298+5.639
• Periodic variability of 6.7GHz methanol masers in G22.357+0.066
• Discovery of four periodic methanol masers and updated light curve for a further one
• Engineering and Science Highlights of the KAT-7 Radio Telescope
• New Periodic 6.7 GHz Class II Methanol Maser Associated with G358.460-0.391
• The environment of the strongest galactic methanol maser
• The shortest periodic and flaring flux variability of a methanol maser emission at 6.7 GHz in G 014.23-00.50
• A note on the periodic methanol masers in G9.62+0.20E
• Discovery of periodic class II methanol masers associated with G339.986-0.425 region
• Variability monitoring of the hydroxyl maser emission in G12.889+0.489

Cited by in corpus (5)

• Long-term multi-frequency maser observations of the intermediate-mass young stellar object G107.298+5.639
• Orientation effect on the ligh curve shape of periodic methanol maser sources
• Maser Flares Driven by Variations in Pumping and Background Radiation
• On the pumping of the CS($v=0$) masers in W51 e2e
• A Unified Maxwell-Bloch Framework for Multi-periodic 6.7 GHz Methanol Flaring in G9.62+0.20E