Results 31 to 40 of about 121 (110)
, 2004 8 pages. 1 figure. Proceedings of the 7th European VLBI Network Symposium held in Toledo, Spain on October 12-15, 2004. Editors: R. Bachiller, F. Colomer, J.-F. Desmurs, P. de Vicente (Observatorio Astronomico Nacional), p. 169-176.
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The photoproduction of circumstellar OH maser shells
The Astronomical Journal, 1982 The structure of OH shells formed from the photodestruction of H2O by ambient UV photons in the thick, expanding envelopes around cool evolved stars is investigated. The properties of the shells are governed mainly by the envelope shielding which in turn is primarily controlled by the mass-loss rate M. The peak OH densities and column densities through
P. J. Huggins, A. E. Glassgold
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Equatorial Enhancement in the Dustiest OH/IR Stars in the Galactic Bulge
The Astrophysical JournalWe have detected the 10 μ m silicate feature and the 11.3 μ m crystalline forsterite feature in absorption in 21 oxygen-rich asymptotic giant branch stars in the Galactic bulge.
Steven R. Goldman +4 more
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Phase–Referencing Observations of Galactic Circumstellar Masers [PDF]
International Astronomical Union Colloquium, 1998 AbstractTwo projects are discussed in which a phase referencing technique is used to determine stellar parallaxes and/or proper motions by means of the circumstellar masers. The observations are special in the sense that both continuum and line sources need to be detected.
Huib Jan van Langevelde +4 more
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Considerations on the Origin of IRAS 19312+1950 Based on Long-term Maser Observations
The Astrophysical JournalIRAS source 19312+1950 (hereafter I19312) is an infrared point source with maser emissions of SiO, H _2 O, and OH molecules. Although initial observations suggested that I19312 might be an evolved star, its characteristics are not fully consistent with ...
Huan-Xue Feng +7 more
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The Hamburg Database of Circumstellar OH Masers [PDF]
Proceedings of the International Astronomical Union, 2012 AbstractA new version of the Hamburg Database of Circumstellar OH Masers at 1612, 1665, and 1667 MHz was released in 2012 January. The database now lists 13170 OH maser observations of stars in the Milky Way. They belong to 6318 different objects and 2324 of them were detected in at least one of the transitions. The database contains flux densities and
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The three-dimensional structure of a circumstellar maser
The Astrophysical Journal, 1984 A 900-day observation of the line profile of the unusual 1667 MHz OH maser in the bipolar nebula OH 231.8+4.2 has indicated that it varies sinusoidally by a factor of about 3, with a period of 684 + or - 40 days. This is in agreement with recent IR observations. The phase of the variations varies strongly with velocity.
P. F. Bowers, M. Morris
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VLBI Synthesis Observations of Circumstellar OH Masers [PDF]
Symposium - International Astronomical Union, 1984 A technique for mapping spectral line sources using closure phase VLBI techniques is described, and some initial results on circumstellar shell sources are presented. The maps show an unresolved point source on the nearside of the shell, but no corresponding source on the far-side of the shell.
R.P. Norris +4 more
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Systematic Search for Water Fountain Candidates Using the Databases of Circumstellar Maser Sources
The Astrophysical Journal Supplement SeriesWater fountains (WFs) are thought to be objects in the morphological evolution of the circumstellar envelopes of low- and intermediate-mass evolved stars, transitioning from spherically symmetric to asymmetric shapes.
Haichen Fan +8 more
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CH3OH Thermal Lines Traces 6.7 GHz CH3OH Maser Variation of High-mass Protostar G353.273+0.641
The Astrophysical JournalThis study reports an analysis of the 6.7 GHz CH _3 OH maser in the high-mass protostar G353.273+0.641 (G353), utilizing data from the Tianma Radio Telescope.
Shi-Min Song +3 more
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