Results 41 to 50 of about 423 (145)
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
openaire +1 more source
Methanol masers as tools to study high-mass star formation [PDF]
, 2007 In this contribution I will attempt to show that the study of Galactic 6.7 and 12.2GHz methanol masers themselves, as opposed to the use of methanol masers as signposts, can yield important conclusions contributing to the understanding of high-mass star ...
Pestalozzi, M.
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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
doaj +1 more source
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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High Resolution Studies of Circumstellar Masers
, 1996 This thesis describes in detail the observational procedures that we have followed and developed to analyze several research projects organized at Onsala since 1990 to study the regions of SiO maser emission at 43 GHz in the circumstellar envelopes of ...
Colomer Sanmartin, Francisco,
core +1 more source
Modelling and observations of molecules in discs around young stars [PDF]
, 2013 This thesis contains a study of molecules within circumstellar discs around young stars. Firstly, the chemistry of a disc around a young, Class 0 protostar is modelled.
Ilee, John David
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