Mapping Observations of 6.7 GHz Methanol Masers with Japanese VLBI Network

Abstract

We have observed 13 methanol maser sources associated with massive star-forming regions; W3(OH), Mon R2, S 255, W 33A, IRAS 18151-1208, G 24.78+0.08, G 29.95-0.02, IRAS 18556+0136, W 48, OH 43.8-0.1, ON 1, Cep A and NGC 7538 at 6.7 GHz using the Japanese VLBI Network (JVN). Twelve of the thirteen sources were detected at our longest baseline of $\sim$50 M$\lambda$, and their images are presented. Seven of them are the first VLBI images at 6.7 GHz. This high detection rate and the small fringe spacing of $\sim$4 milli-arcsecond suggest that most of the methanol maser sources have compact structure. Given this compactness as well as the known properties of long-life and small internal-motion, this methanol maser line is suitable for astrometry with VLBI.

15 pages, 13 figures, accepted for publication in PASJ

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Cited by in corpus (23)

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• Observations of 6.7 GHz Methanol Masers with EAVN I: VLBI Images of the first Epoch of Observations
• The Spatial Distribution of Organics toward the High-Mass YSO NGC 7538 IRS9
• Planar infall of CH3OH gas around Cepheus A HW2
• EVN observations of 6.7 GHz methanol maser polarization in massive star-forming regions
• KFPA Examinations of Young STellar Object Natal Environments (KEYSTONE): Hierarchical Ammonia Structures in Galactic Giant Molecular Clouds
• Rotating and infalling motion around the high-mass young stellar object Cepheus A-HW2 observed with the methanol maser at 6.7 GHz
• Dynamics of the 6.7 and 12.2 GHz methanol masers around Cepheus A HW2
• The First Very Long Baseline Interferometry Image of 44 GHz Methanol Maser with the KVN and VERA Array (KaVA)
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: 278 GHz Class I Methanol Masers
• A Synchronized Variation of the 6.7 GHz Methanol Maser in Cepheus A
• EVN observations of 6.7 GHz methanol masers in clusters of massive young stellar objects
• 6.7GHz methanol maser variability in Cepheus A
• Magnetic field regulated infall on the disc around the massive protostar Cepheus A HW2
• Bursting Activity in a High-Mass Star-Forming Region G33.64-0.21 Observed with the 6.7 GHz Methanol Maser
• New evidence for Dicke's superradiance in the 6.7 GHz methanol spectral line in the interstellar medium
• EVN observations of 6.7 GHz methanol maser polarization in massive star-forming regions IV. Magnetic field strength limits and structure for 7 additional sources
• Internal Motion of 6.7-GHz Methanol Masers in H II Region S269
• Maser Flares Driven by Variations in Pumping and Background Radiation
• Distribution and excitation of thermal methanol in 6.7 GHz maser bearing star-forming regions; I. The nearby source Cepheus A
• Masers in star forming regions
• Physical conditions around high-mass young star-forming objects via simultaneous observations of excited OH and methanol masers