Results 161 to 170 of about 1,279 (175)

The 36 GHz Class I Methanol Maser in NGC 4945: A Tracer of Active Galactic Nucleus-driven Outflow–Interstellar Medium Interaction

Astrophysical Journal Letters
Extragalactic Class I methanol masers are well-established tracers of bar-driven shocks in several nearby galaxies, but whether active galactic nucleus (AGN)-driven outflows can also excite such masers has remained unclear.
Xi Chen, Tian Yang, Shimin Song, T. McCarthy, Xiaoyun Xu, S. Ellingsen, S. Breen   +6 more
semanticscholar   +1 more source

Interstellar scattering of maser radiation

1993
Interstellax scattering of pulsars, extragalactic sources, and galactic masers is used to discuss the overall galactic distribution of scattering material and the implied angular scattering vs galactic coordinates. I discuss the prospects for observing diffractive and refractive scintillations of maser signals.
openaire   +1 more source

Maser action without inversion in interstellar space

Optics Communications, 1998
Abstract It is recognized that interstellar 6.7 and 12.2 GHz methanol masers toward Class II sources are associated with each other and coexist toward ultracompact HII regions. Therefore we suggest a new excitation mechanism – methanol masers without population inversion.
Hanping Liu, Jin Sun
openaire   +1 more source

Magnetic fields in interstellar water masers

2008
We report the first detection of Zeeman splitting in the (616−523) rotational transition of interstellar H2O masers. The measurements of Stokes parameter V and I spectra (circular polarization) have been performed at the MPIfR 100-m telescope. Depending on the hyperfine transition that is actually masing, we derive typical magnetic field strengths of B‖
D. Fiebig, R. Güsten
openaire   +1 more source

A monitoring program of interstellar OH and H2O masers

1993
We obtained spectra of a set of interstellar-OH and H2O masers at intervals of a few days to about a week throughout a period of about 5 months. The purpose was to determine whether interstellar scintillation and scattering processes contribute to maser variability.
John H. Simonetti, P. J. Diamond, Jeffrey A. Uphoff, David Boboltz, Brian Dennison   +4 more
openaire   +1 more source

Angular structure and motions of interstellar masers

2008
A brief historical account is given of the discovery of OH emission and the experiments that led to the identification of the radiation mechanism as maser amplification. An outline is presented of the progress by the MIT, CfA and Jodrell Bank groups in mapping the prototypical maser, W3(OH).
openaire   +1 more source

On the possibility of registration of Dirac monopole by nonlinear effects in the emission of interstellar masers

, 1977
S. Rautian, V. Safonov, G. Smirnov
semanticscholar   +1 more source

Interstellar scattering of radiatin from H2O masers in W49 and Sgr B2

AIP Conference Proceedings, 1988
C R Gwinn, M J Reid, Gwinn C R
exaly  

Interstellar Atoms, Molecules, and Cosmic Masers

2023
openaire   +1 more source

A feasible excitation mechanism for interstellar Class II methanol masers

Optical and Quantum Electronics, 2008
J R Förster
exaly