Results 91 to 100 of about 121 (110)

Circumstellar Masers in the Galactic Center

2003
Blind and targeted surveys for maser emission (OH, H2O, and SiO) in the central degree (≤ 150 pc) of the Galactic center will be discussed, with the emphasis on masers in OH/IR stars. Using the masers, some recent clues about the kinematics and evolution of the central part of the Milky Way galaxy will be given.
openaire   +1 more source

Optical pumping of circumstellar SiO masers

1995
We investigate the influence of the photospheric line spectrum on the optical pumping of circumstellar CO. As pump radiation we consider in particular the photospheric spectrum of a cool carbon star (T eff =2600 K). This spectrum shows deep absorption lines in the wavelength range of the pump lines (4.6 μ). Of particular importance for the pump process
E. Rausch, W. H. Kegel, T. Tsuji
openaire   +1 more source

FG3: Spatial and frequency modeling of circumstellar masers

Vistas in Astronomy, 1997
Abstract We have developed a computer program (called “FG3”) that is useful to model images of spectral line emission. We have applied it successfully to the study of maser emission in the circumstellar envelopes of late-type stars. The program will search for maser sources, blended spatially and in frequency, and fit 3D Gaussians to them.
F. Colomer, K.M. Menten, M.J. Reid
openaire   +1 more source

Proper Motions of Water Masers in Circumstellar Shells

International Astronomical Union Colloquium, 1998
AbstractWe present measurements of proper motions for circumstellar water maser observations obtained with the VLBA. Results of the observations and modeling indicate that the water masers exist in a kinematically complex region of the circumstellar envelope. A change in position of the maser spots as a function of velocity is discussed.
K. B. Marvel, P. J. Diamond, A. J. Kemball   +2 more
openaire   +1 more source

Molecular catastrophes and circumstellar SiO masers

1993
Understanding the complex SiO maser regions of highly evolved stars can be improved through multiwavelength studies of 'premaser' stars, such as M0-M4 giants and semiregular variables, which can be placed on normal H-R diagrams unlike most of the OH-IR stars.
openaire   +1 more source

Submillimetre water masers in circumstellar envelopes -- II. Variability

Monthly Notices of the Royal Astronomical Society, 1996
J A Yates, Cohen R J
exaly  

Circumstellar Clouds and Masers

2006
openaire   +1 more source

VLBI astrometry of circumstellar OH masers: Proper motions and parallaxes of four AGB stars

Astronomy and Astrophysics, 2003
Huib Jan Van Langevelde, P J Diamond, R T Schilizzi   +2 more
exaly  

The chronological sequence of circumstellar masers - Identifying proto-planetary nebulae

Astrophysical Journal, 1989
B M Lewis
exaly  

Circumstellar water masers

Lecture Notes in Physics, 2005
J A Yates, Yates J A
exaly