Results 31 to 40 of about 176 (166)

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

The electron–cyclotron maser for astrophysical application [PDF]

The Astronomy and Astrophysics Review, 2006
The electron–cyclotron maser is a process that generates coherent radiation from plasma. In the last two decades, it has gained increasing attention as a dominant mechanism of producing high-power radiation in natural high-temperature magnetized plasmas.
openaire   +2 more sources

Statistical Scale Analyses of a Diurnal Periodicity in Auroral Kilometric Radiation, Observed by Wind/WAVES

Journal of Geophysical Research: Space Physics, Volume 131, Issue 9, September 2026.
Abstract The Earth's strongest natural radio emission is Auroral Kilometric Radiation (AKR), which is correlated with auroral intensity, and is a barometer for space weather. AKR is generated by the electron cyclotron maser instability, with sources on auroral field lines. Previous work on AKR and radio emissions from other planets (or stars) points to
Alexandra Ruth Fogg, S. Wu, C. M. Jackman, S. J. Walker, M. J. Rutala, C. K. Louis, S. M. Ivanov, L. Lamy, J. E. Waters, D. K. Whiter   +9 more
wiley   +1 more source

The Discovery of the Zeeman Effect in 38 GHz Class II Methanol Masers

The Astrophysical Journal, 2023
Magnetic fields likely play an important role in star formation, but the number of directly measured magnetic field strengths remains scarce. We observed the 38.3 and 38.5 GHz Class II methanol (CH _3 OH) maser lines toward the high-mass star-forming ...
E. Momjian, A. P. Sarma
doaj   +1 more source

Coincident ENA and Narrowband Radio Emissions as Diagnostics of Inward Plasma Transport at Saturn

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract Saturn's kilometric radiation (SKR) and Energetic Neutral Atom (ENA) emissions are important diagnostics of the planet's magnetospheric dynamics, intensifying during global plasma injections and displaying characteristic planetary periodicity. Related to the SKR emissions are myriametric narrowband radio emissions that typically appear in the ...
J. Kinrade, S. V. Badman, S. Y. Wu, C. Paranicas, C. M. Jackman, L. S. Clare, C. K. Louis   +6 more
wiley   +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

Low Frequency Extensions of Cyclotron Maser Instability‐Generated Radio Emission: A Statistical View From Cassini at Saturn

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract The Cassini spacecraft spent 13 years orbiting Saturn, quasi‐continuously measuring Saturn's radio emissions. One of the key elements of the radio spectrum at Saturn is the Saturn Kilometric Radiation (SKR), and several studies have been written on events called Low Frequency Extensions (LFEs) which represent strong, continuous extensions of ...
C. M. Jackman, A. R. Fogg, S. W. H. Cowley, G. Provan, H. Adamski, N. M. Besch, D. M. Hollman, S. Walker, M. J. Rutala, L. Lamy, C. K. Louis, E. P. O’Dwyer   +11 more
wiley   +1 more source

Peculiar Spectral Property of Coherent Radio Emission from a Hot Magnetic Star: The Case of an Extreme Oblique Rotator

The Astrophysical Journal, 2023
We report ultra-wideband (0.4–4.0 GHz) observation of coherent radio emission via electron cyclotron maser emission (ECME) produced by the hot magnetic star HD 142990.
Barnali Das, Poonam Chandra
doaj   +1 more source

Earthward Propagated Auroral Kilometric Radiation: Observations From Polar

Geophysical Research Letters, Volume 53, Issue 12, 28 June 2026.
Abstract Auroral Kilometric Radiation (AKR), the strongest natural radio emission from Earth's magnetosphere, has been primarily observed in space. It is generally understood to propagate anti‐Earthward and be detected at large radial distances, while Earthward‐directed waves are thought to be blocked by the ionosphere. Surprisingly, AKR‐like emissions
Olha Melnychenko, Siyuan Wu, Daniel K. Whiter, Baptiste Cecconi, Claire Baskvetich   +4 more
wiley   +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