Detection of the longest periodic variability in 6.7 GHz methanol masers G5.900-0.430

Abstract

Long term monitoring observations with the Hitachi 32-m radio telescope of the 6.7 GHz methanol masers associated with the high mass star-forming region G5.900-0.430 is presented. A period of flux variability at approximately 1260 days, is detected in the features at VLSR = 9.77 and 10.84 km/s while a secondary shorter period, 130.6 days, is determined for the 0.66 km/s feature. This is only the second source which has two different periods. The period of ~1260 days is approximately twice as long as the longest known period of 6.7 GHz methanol masers. The variability pattern of the symmetric sine curves and the consistency with the expected period-luminosity relation suggest that the mechanism of maser flux variability of 9.77 and 10.84 km/s features in this source can be explained by protostellar pulsation instability. On the other hand, because the 0.66 km/s feature has an intermittent and asymmetric variability profile, we propose this feature is explained by the CWB or spiral shock models. Obtaining the spatial distribution of the 0.66 km/s feature using an VLBI will lead to a better understanding of this source.

References in corpus (12)

• ATLASGAL --- properties of a complete sample of Galactic clumps
• The Arecibo Methanol Maser Galactic Plane Survey--I: Data
• Trigonometric Parallaxes of Star Forming Regions in the Scutum Spiral Arm
• On the Relationship of UC H II Regions and Class II Methanol Masers: I. Source Catalogs
• A heat-wave of accretion energy traced by masers in the G358-MM1 high-mass protostar
• On the Class II Methanol Maser Periodic Variability due to the Rotating Spiral Shocks in the Gaps of Disks Around Young Binary Stars
• Monitoring observations of 6.7 GHz methanol masers
• Discovery of four periodic methanol masers and updated light curve for a further one
• New Periodic 6.7 GHz Class II Methanol Maser Associated with G358.460-0.391
• Periodic Flare of the 6.7 GHz Methanol Maser in IRAS22198+6336
• Detection of periodic flares in 6.7 GHz methanol masers G45.804-0.356 and G49.043-1.079
• Orientation effect on the ligh curve shape of periodic methanol maser sources

Cited by in corpus (1)

• A Unified Maxwell-Bloch Framework for Multi-periodic 6.7 GHz Methanol Flaring in G9.62+0.20E