Results 41 to 50 of about 173 (158)

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

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

Frequency Extensions of Auroral Kilometric Radiation: The Key to Unlocking Earth's Radio Response to Substorms

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract Auroral kilometric radiation (AKR) provides a sensitive probe of magnetospheric dynamics during substorms. We analyze an extended data set of AKR bursts observed by the WIND spacecraft to investigate how the frequency structure of AKR responds to substorm onset and evolution.
Simon James Walker, Caitríona M. Jackman, Alexandra R. Fogg, Siyuan Wu, James E. Waters   +4 more
wiley   +1 more source

Masers and Star Formation Activities in W51A

The Astronomical Journal
Concurrently with the maser flare observed in W51-North during the 3 month monitoring of H _2 O, NH _3 , and CH _3 OH maser variability from 2020 January to April using the Tianma 65 m Radio Telescope, we conducted Very Large Array mappings for these ...
Yan-Kun Zhang, Xi Chen, You-Xin Wang, Shi-Min Song, Jun-Ting Liu, Ying Lu   +5 more
doaj   +1 more source

Evidence of an Extended Alfvén Wing System at Enceladus: Cassini's Multi‐Instrument Observations

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract We report in situ evidence for Enceladus' Alfvén wing system and its coupling with Saturn's ionosphere, based on multi‐instrument observations from the Cassini spacecraft. Analysis of 36 events, including 13 from non‐flyby paths, confirms the existence of a Main Alfvén Wing (MAW) current system generated at Enceladus, and associated Reflected ...
L. Z. Hadid, T. Chust, J.‐E. Wahlund, M. W. Morooka, E. Roussos, O. Witasse, J. Rabia, D. Pisa, K. Kim, N. J. T. Edberg, A. M. Rymer, L. Lamy, S. Kotsiaros, S. Aizawa, A. Jeandet, R. Modolo, N. André, P. Canu, C. F. Bowers, X. Jia, A. J. Coates, G. H. Jones, A. Parsec‐Wallis, O. Agiwal, M. K. G. Holmberg, Q. Nénon, H. Cao, W. S. Kurth, M. K. Dougherty   +28 more
wiley   +1 more source

A Personal Voyage Among Earth and Space Physics Disciplines

Perspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.
Abstract I have organized my thoughts in an autobiographical way in relation to the several distinct phases of my career encompassing Earth and space physics. I discuss atmospheric and space physics topics of interest to me in an international context, and I emphasize the value of community activities and international conferences for the interchange ...
Michael J. Rycroft
wiley   +1 more source

Numerical simulation of astrophysical cyclotron-maser emission [PDF]

2013 38th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2013
Numerical simulations have been conducted at the University of Strathclyde to study the spatial growth rate and emission topology of the cyclotron maser instability responsible for auroral magnetospheric radio emission from stars and planets and intense non-thermal radio emission in other astrophysical contexts.
Speirs, D. C., McConville, S. L., Gillespie, K. M., Phelps, A.D.R., Cross, A. W., Ronald, K.   +5 more
openaire   +3 more sources

Quasilinear Wave‐Particle Analysis in the Source Region of Jovian Kilometric Radio Emission

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract Jovian broadband kilometric emission (bKOM) is observed by the Juno spacecraft within a source region in the northern hemisphere near the equatorward edge of the auroral oval. A well‐developed upward loss cone is the free‐energy source of the bKOM.
P. H. Yoon, J. D. Menietti, F. Allegrini, W. S. Kurth, J. B. Faden, G. B. Hospodarsky, J. E. P. Connerney, S. J. Bolton   +7 more
wiley   +1 more source

AKR Observations From All Local Times Indicate Substorm Activity

Journal of Geophysical Research: Space Physics, Volume 130, Issue 9, September 2025.
Abstract Auroral Kilometric Radiation (AKR) is known to present emission at lower frequencies near substorm onset, corresponding to activation of higher altitude sources along auroral magnetic field lines and acting as a proxy of the vertical distribution of acceleration processes during these events.
J. E. Waters, L. Lamy, J. Coxon, C. M. Jackman, C. J. Lao, C. Forsyth, A. R. Fogg   +6 more
wiley   +1 more source

Statistical Study on L‐O Mode Saturn Kilometric Radiation

Geophysical Research Letters, Volume 52, Issue 15, 16 August 2025.
Abstract Based on the 13 years‐long observation of Saturn kilometric radiation (SKR) by the Cassini/Radio and Plasma Wave Science instrument, this study derives statistics for left‐hand (L‐O) mode SKR emissions. These emissions span a frequency range from below 10 kHz to approximately 1,000 kHz, with spectral flux densities ranging between 10−24 and 10−
Junhao Pan, Siyuan Wu, Shengyi Ye, Georg Fischer, Laurent Lamy, Philippe Zarka, Ulrich Taubenschuss   +6 more
wiley   +1 more source