Results 51 to 60 of about 154 (145)
On the Structure of the Sagittarius Spiral Arm in the Inner Milky Way
The Astronomical JournalWe report measurements of trigonometric parallax and proper motion for two 6.7 GHz methanol and two 22 GHz water masers located in the far portion of the Sagittarius spiral arm as part of the BeSSeL Survey.
S. B. Bian +8 more
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Distribution Properties of the 6.7 GHz Methanol Masers and Their Surrounding Gases in the Milky Way
The Astrophysical JournalAn updated catalog consisting of 1092 6.7 GHz methanol maser sources is reported in this work. Additionally, the NH _3 (1, 1), NH _3 (2, 2), and NH _3 (3, 3) transitions were observed toward 214 star-forming regions using the Shanghai Tianma radio ...
Tian Yang +6 more
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Astronomy & AstrophysicsContext. Massive stars have a profound impact on their environments, shaping the interstellar medium through intense radiation and stellar winds. The expanding shells they produce can potentially trigger star formation. Aims.
Cichowolski S. +5 more
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Inversion mechanism and maser emission in the interstellar medium [PDF]
Proceedings of 2nd MCCT-SKADS Training School. Radio Astronomy: fundamentals and the new instruments — PoS(2nd MCCT-SKADS), 2009 MASER emission in the astronomical environment is the subject of this lecture. In order to explain the origin of this phenomenon, the problem of molecular excitation in a galactic molecular cloud is treated formulating the equations of statistical equilibrium in a stationary situation.
openaire +1 more source
Survey of S-type AGB Stars Using the KVN Four-band Receiving System: SMASTES II
The Astronomical JournalWe present the observational results of Simultaneous Multi-mAser Survey Toward Evolved Stars (SMASTES) II for 150 S-type asymptotic giant branch stars. Observations have been performed from 2023 September to 2024 March using the upgraded wide four-band ...
Seong-Min Son +5 more
doaj +1 more source
Inner Workings: Astronomers are redrawing our corner of the Milky Way. [PDF]
Proc Natl Acad Sci U S A, 2021 Croswell K.
europepmc +1 more source
Pumping the interstellar (6, 3) ammonia maser
The Astrophysical Journal, 1991 A numerical model of the excitation of ammonia in dense interstellar clouds predicts strong maser emission in various inversion doublet lines when infrared pumping to the lowest vibrationally excited state is included. Specifically the (6,3) transition mases, while the (5,3) and (4,3) transitions are in normal emission, as observed in W51.
Ronald D. Brown, Dinah M. Cragg
openaire +1 more source
The Astrophysical JournalWe report on the periodic flux variations in the 6.7 GHz CH _3 OH maser associated with the high-mass protostar G353.273+0.641, based on 13 yr of monitoring mainly by the Hitachi 32 m telescope.
Sohta Harajiri +5 more
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The Astronomical JournalFrom 2019 January to June, the high-mass young stellar object G358.93-0.03 underwent a remarkable accretion burst. Detecting variations in the physical and kinematic environments during episodic accretion is essential for exploring such events. Searching
Shi-jie Zhang +5 more
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Survey of Oxygen-rich AGB Stars Using the KVN 4 Receiving Bands—SMASTES. I.
The Astronomical JournalSimultaneous observations of 19 H _2 O and SiO maser and thermal lines were performed toward 155 M-type oxygen-rich (O-rich) AGB stars. We used the upgraded four-band (22/43/86/129 GHz) wide receiving system of the Korean VLBI Network (KVN).
Hyeon Baek +5 more
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