Results 31 to 40 of about 423 (145)

3D velocity fields from methanol and water masers in an intermediate-mass protostar [PDF]

, 2012
We report multi-epoch VLBI observations of molecular masers towards the high-mass star forming region AFGL 5142, leading to the determination of the 3D velocity field of circumstellar molecular gas at radii 3OH maser emission enabled, for the first time,
MOSCADELLI, Luca, SANNA, ALBERTO, Goddi, C.   +2 more
core   +1 more source

Circular polarization of water masers in the circumstellar envelopes of late type stars

, 2002
We present circular polarization measurements of circumstellar H2O masers. The magnetic fields in circumstellar envelopes are generally examined by polarization observations of SiO and OH masers.
W. H. T. Vlemmings, Vlemmings, W.H.T., Van Langevelde, H. J., P. J. Diamond, Diamond, P. J., H. J. van Langevelde, Diamond, P.J., Vlemmings, W. H T, Langevelde, H.J. van   +8 more
core   +1 more source

Inferences from the kinematic properties of 6.7 GHz methanol masers [PDF]

, 2007
Context. It is now well established that the strong and widespread 6.7 GHz methanol masers are associated with young high mass stars. A still unsolved question is where in the circumstellar environment the masers arise.
Sobolev, A. M., Butner, H., H. Butner, van der Walt, D. J., D. J. van der Walt, A. M. Sobolev   +5 more
core   +1 more source

Mapping the circumstellar SiO maser emission in R Leonis [PDF]

Astronomy & Astrophysics, 2007
accepted for publication in A& ...
Soria-Ruiz, R., Alcolea, J., Colomer, F., Bujarrabal, V., Desmurs, J. -F.   +4 more
openaire   +2 more sources

FAST Detection of OH Emission in the Carbon-rich Planetary Nebula NGC 7027

The Astrophysical Journal
We present the first detection of the ground-state OH emission line at 1612 MHz toward the prototypical carbon-rich planetary nebula (PN) NGC 7027, utilizing the newly installed ultrawideband (UWB) receiver of the Five-hundred-meter Aperture Spherical ...
Xu-Jia Ouyang, Yong Zhang, Chuan-Peng Zhang, Peng Jiang, Jun-ichi Nakashima, Xi Chen, Hai-Hua Qiao, Xu-Ying Zhang, Hao-Min Sun, Xiao-Hu Li, Albert Zijlstra   +10 more
doaj   +1 more source

Linear polarization of hydroxyl masers in circumstellar envelope outer regions

, 2012
International audienceA recent polarimetric survey of OH masers in a large sample of AGB and post-AGB stars revealed widespread occurrence of polarized features. We made a statistical analysis of the polarization properties of this large data set.
Gérard, Éric, Wolak, P., Szymczak, M.
core   +1 more source

Investigating Asymmetry Development from SiO to H2O Maser Regions in VX Sagittarii

The Astronomical Journal
Simultaneous very-long-baseline interferometry monitoring observations of H _2 O and SiO masers toward VX Sagittarii were conducted from 2014 February to 2019 January.
Dong-Hwan Yoon, Se-Hyung Cho, Youngjoo Yun, Haneul Yang, Jaeheon Kim   +4 more
doaj   +1 more source

Infrared Spectral Energy Distribution Modeling of Velocity Excess in Maser Sources: Identifying Incipient Water Fountain Candidates

The Astrophysical Journal
We investigated whether “velocity excess” in circumstellar maser lines can diagnose the earliest evolutionary phases of water fountains (WFs). Here, we define “velocity excess” as maser emission (e.g., H _2 O 22.235 GHz or OH 1665/1667 MHz) detected at ...
Jia-Yong Xie, Jun-ichi Nakashima, Yong Zhang   +2 more
doaj   +1 more source

Circumstellar masers

, 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.
openaire   +2 more sources

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
openaire   +1 more source