Results 11 to 20 of about 423 (145)
A database of circumstellar OH masers [PDF]
Astronomy & Astrophysics, 2007 AbstractWe present a new database of circumstellar OH masers at 1612, 1665, and 1667 MHz. The database contains 10774 observations and 2274 stars with OH maser emission detected. The database contains flux densities and velocities of the two strongest maser peaks, the expansion velocity of the shell and the radial velocity of the star.
Engels, D., Bunzel, F.
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A Search for Asymmetric Kinematic Components in Circumstellar Envelopes Using OH Main Line Masers
The Astrophysical JournalCircumstellar OH maser lines are useful for studying the dynamics of the circumstellar envelope (CSE) around evolved stars. This study aims to identify CSEs around cold stars, which exhibit deviations from the spherical expansion, by comparing the ...
Jia-Yong Xie +2 more
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Excited-state OH Masers in the Water Fountain Source IRAS 18460-0151
The Astrophysical Journal LettersWater fountain objects are generally defined as evolved stars with low to intermediate initial mass accompanied by high-velocity molecular jets detectable in the 22.235 GHz H _2 O maser line.
Xu-Jia Ouyang +5 more
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Variability of masers in circumstellar shells on timescales of decades
Proceedings of the International Astronomical Union, 2007 AbstractBased on a 15–20 year long monitoring program of H2O masers and new observations of OH masers discovered 35 years ago, we studied the variability of maser emission in AGB stars over timescales of decades. The H2O maser features in the semi-regular variable stars RX Boo and SV Peg, and of the Mira stars U Her and R Cas, showed strong ...
Engels, D. +3 more
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An Updated Reference Frame for the Galactic Inner Parsec
The Astrophysical Journal, 2023 Infrared observations of stellar orbits about Sgr A* probe the mass distribution in the inner parsec of the Galaxy and provide definitive evidence for the existence of a massive black hole.
Jeremy Darling +5 more
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Recent mass ejection from AGB star W Hya
Vietnam Journal of Science, Technology and Engineering, 2022 We analyse archival ALMA (Atacama Large Millimeter/submillimeter Array) observations of two molecular line emissions, 12CO(3-2) and 29SiO(8-7), from oxygen-rich AGB (Asymptotic Giant Branch) star W Hya.
D.T. Hoai +6 more
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Detection of a High-velocity Jet from MWC 349A Traced by Hydrogen Recombination Line Maser Emission
The Astrophysical Journal Letters, 2023 MWC 349A is one of the rare stars known to have hydrogen radio recombination line (RRL) masers. The bright maser emission makes it possible to study the dynamics of the system at milliarcsecond (mas) precision.
Sirina Prasad +7 more
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Methanol Masers—Are They in Circumstellar Disks? [PDF]
International Astronomical Union Colloquium, 1998 AbstractSince the discovery of the 12.2 and 6.7 GHz methanol maser lines, these masers have been studied in great detail. Even in the earliest studies, it appeared that in some fraction of the sources, the maser spots were arranged in lines. This contrasts with the well-studied OH and water masers, in which the masers tended to be clustered almost ...
R. P. Norris +2 more
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VLBI observations of H2O and CH3OH masers in two high-mass YSOs [PDF]
, 2007 We have conducted phase-reference VLBI observations of H2O and CH3OH masers toward two high-mass star forming regions, Sh 2-255 IR and AFGL 5142. In Sh 2-255 infrared water masers are aligned along a direction close to the orientation of a large scale H2
MOSCADELLI, Luca +4 more
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Modeling of the High-velocity Jet Powered by the Massive Star MWC 349A
The Astrophysical Journal, 2023 MWC 349A is a massive star with a well-known circumstellar disk rotating following a Keplerian law, and an ionized wind launched from the disk surface.
Antonio Martínez-Henares +8 more
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