Results 31 to 40 of about 2,871 (139)

Polarization morphology of SiO masers in the circumstellar envelope of the AGB star R Cassiopeiae [PDF]

, 2013
Silicon monoxide maser emission has been detected in the circumstellar envelopes of many evolved stars in various vibrationally-excited rotational transitions. It is considered a good tracer of the wind dynamics close to the photosphere of the star.
Assaf, K. A., Diamond, P. J., Gray, M. D., Richards, A. M. S.   +3 more
core   +1 more source

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, R.S. Booth, P.J. Diamond, D.A. Graham, L-A. Nyman   +4 more
openaire   +1 more source

Database of Molecular Masers and Variable Stars [PDF]

, 2018
We present the database of maser sources in H2O, OH and SiO lines that can be used to identify and study variable stars at evolved stages. Detecting the maser emission in H2O, OH and SiO molecules toward infrared-excess objects is one of the methods of ...
Ladeyschikov, D. A., Nakashima, J. -I., Sobolev, A. M.   +2 more
core   +1 more source

Excited-state OH Masers in the Water Fountain Source IRAS 18460-0151

The Astrophysical Journal Letters
Water 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, Yong Zhang, Juan Li, Jun-ichi Nakashima, Xi Chen, Hai-Hua Qiao   +5 more
doaj   +1 more source

The Masers Towards IRAS 20126+4104

, 2005
We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to the central ...
Cohen, R. J., Edris, K. A., Etoka, S., Fuller, G. A.   +3 more
core   +1 more source

A Search for Asymmetric Kinematic Components in Circumstellar Envelopes Using OH Main Line Masers

The Astrophysical Journal
Circumstellar 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, Jun-ichi Nakashima, Yong Zhang   +2 more
doaj   +1 more source

Ground-State SiO Maser Emission Toward Evolved Stars

, 2004
We have made the first unambiguous detection of vibrational ground-state maser emission from SiO toward six evolved stars. Using the Very Large Array, we simultaneously observed the v=0, J=1-0, 43.4-GHz, ground-state and the v=1, J=1-0, 43.1-GHz, first ...
Alcolea J., Baudry A., Bujarrabal V., D. A. Boboltz, Herpin F., Jewell P. R., Lucas R., M. J. Claussen, Rausch E.   +8 more
core   +1 more source

Excited-state OH Mainline Masers in AU Geminorum and NML Cygni

, 2007
Excited-state OH maser emission has previously been reported in the circumstellar envelopes of only two evolved stars: the Mira star AU Geminorum and the hypergiant NML Cygni.
Baudry A., Bujarrabal V., Diamond P. J., Engels D., Habing H. J., He J. H., Herman J., Laura K. Zschaechner, Loránt O. Sjouwerman, Mark J. Claussen, Masheder M. R. W., Nguyen, Nyman L., Olnon F. M., Sylvester R. J., Ulvestad J. S., van Genderen A. M., Vincent L. Fish, Ylva M. Pihlström   +18 more
core   +1 more source

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

Faraday Depolarization and Circumstellar SiO Masers

The Astrophysical Journal, 1997
Calculations are performed for the creation and transport of linearly polarized maser radiation in the presence of Faraday depolarization due to free electrons. Attention is limited to magnetic field strengths for which the characteristic Zeeman splitting gΩ is much less than the spectral line breadth Δω—the regime that ordinarily is appropriate for ...
Bradley K. Wallin, William D. Watson
openaire   +1 more source