A new submillimeter Class I methanol maser at 345.903 GHz near the massive protostar S255IR NIRS3

@misc{salii2026submillimeter,
  title = {{A new submillimeter Class I methanol maser at 345.903 GHz near the massive protostar S255IR NIRS3}},
  author = {Svetlana Salii and Igor Zinchenko and Andrej Sobolev},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.23187},
  eprint = {2610.23187},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.23187},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - A new submillimeter Class I methanol maser at 345.903 GHz near the massive protostar S255IR NIRS3
AU  - Svetlana Salii
AU  - Igor Zinchenko
AU  - Andrej Sobolev
PY  - 2026
DA  - 2026/10/16
PB  - arXiv
DO  - 10.48550/arxiv.2610.23187
UR  - https://arxiv.org/abs/2610.23187
AB  - We present results of further investigation of radio emission from the remarkable molecular core S255IR-SMA1 harboring a ∼ 20 Msun young stellar object NIRS3 which exhibited a disk-mediated accretion burst in 2015. Our study is based on observations of this object with ALMA in Band 7 with the longest baselines, which provide an angular resolution of ∼15 mas. The obtained data reveal several spots in the bright and narrow methanol 16(1) − 15(2) A− line emission at 345.903 GHz. These spots are located close to H_2O masers, knots in the jet and arc-like structures seen in submillimeter continuum. At the same time, they are far away from the peaks of the Class II methanol maser spots. High brightness temperatures and small line widths of the 345.903 GHz line emission indicate that this emission has a maser nature. Association with the shock tracers tells that these masers belong to Class I methanol maser category. Non-LTE analysis of the physical parameters which lead to population inversion of 16(1) − 15(2) A− transition shows that some known rare Class I methanol maser transitions are also inverted under these conditions.
ER  -