Results 71 to 80 of about 1,279 (175)

Distribution Properties of the 6.7 GHz Methanol Masers and Their Surrounding Gases in the Milky Way

open access: yesThe Astrophysical Journal
An 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
doaj   +1 more source

THE INTERSLELLAR OH AND $H_{2}O$ MASERS

open access: yes, 1998
Author Institution: Department of Physics, Beijing Normal UniversityThe masers in the regions of star formation are mainly both $H_{2}O$ and OH masers. They are related to the early evolution of stars.
Sun, Jin, Liu, Hanping
core  

Survey of S-type AGB Stars Using the KVN Four-band Receiving System: SMASTES II

open access: yesThe Astronomical Journal
We 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

Inversion mechanism and maser emission in the interstellar medium [PDF]

open access: yesProceedings 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

Periodic 6.7 GHz CH3OH Maser Emission in G353.273+0.641: First Candidate for a Pulsating High-mass Protostar

open access: yesThe Astrophysical Journal
We 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
doaj   +1 more source

Pumping the interstellar (6, 3) ammonia maser

open access: yesThe 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

Non-equilibrium processes in interstellar molecules

open access: yes, 1979
The types of nonequilibrium emission and absorption by interstellar molecules are summarized. The observed brightness emission temperatures of compact OH and H2O sources are discussed using the concept of maser amplification.
Strelnitskiy, V. S.
core  

OH and H

open access: yes, 1999
Positions and spectra of 1665 MHz OH and 23 235 MHz H2O masers in 74 star-forming regions are presented. This supplement provides an electronic version of the complete VLA database of interstellar masers observed by Forster & Caswell (1989).
J. L. Caswell, J. R. Forster
core   +1 more source

Variabilities of Methanol Maser and Thermal Molecular Lines from an Accretion Burst Source G358.93-0.03

open access: yesThe Astronomical Journal
From 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
doaj   +1 more source

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