3 research outputs found

    The methanol emission in the J1J0J_1-J_0 A+^{-+} line series as a tracer of specific physical conditions in high-mass star-forming regions

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    We present results of the investigations of the properties of the methanol J1J0J_1 - J_0 A+^{-+} line series motivated by the recent serendipitous detection of the maser emission in the 14114014_1 - 14_0 A+^{-+} line at 349~GHz in S255IR-SMA1 soon after the accretion burst. The study includes further observations of several lines of this series in S255IR with the SMA, a mini-survey of methanol lines in the 0.8 mm range toward a sample of bright 6.7~GHz methanol maser sources with the IRAM-30m telescope, and theoretical modeling. We found that the maser component of the 14114014_1 - 14_0 A+^{-+} line in S255IR decayed by more than order of magnitude in comparison with that in 2016. No clear sign of maser emission is observed in other lines of this series in the SMA observations except the 71707_1 - 7_0 A+^{-+} line where an additional bright component is detected at the velocity of the maser emission observed earlier in the 14114014_1 - 14_0 A+^{-+} line. Our LVG model constrains the ranges of the physical parameters that matches the observed emission intensities. No obvious maser emission in the J1J0J_1 - J_0 A+^{-+} lines was detected in the mini-survey of the 6.7~GHz methanol maser sources, though one component in NGC7538 may represent a weak maser. In general, the maser effect in the J1J0J_1 - J_0 A+^{-+} lines may serve as a tracer of rather hot environments and in particular luminosity flaring events during high mass star formation.Comment: 16 pages, 12 figure

    Recent updates on the Maser Monitoring Organisation

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    The Maser Monitoring Organisation (M2O) is a research community of telescope operators, astronomy researchers and maser theoreticians pursuing a joint goal of reaching a deeper understanding of maser emission and exploring its variety of uses as tracers of astrophysical events. These proceedings detail the origin, motivations and current status of the M2O, as was introduced at the 2021 EVN symposium