Results 41 to 50 of about 176 (166)

Radiative Instabilities in Three-dimensional Astrophysical Masers [PDF]

The Astrophysical Journal, 1995
Inherent instabilities in the radiative transfer for astrophysical masers have been recognized and calculated in the linear maser idealization in our previous investigations. The same instabilities are now shown to occur in the more realistic, three-dimensional geometries.
Gerardo A. Scappaticci, William D. Watson   +1 more
openaire   +1 more source

On the Detection of Low‐Frequency Planetary Radio Emission With an Orbiting Interferometer

Radio Science, Volume 61, Issue 6, June 2026.
Abstract The magnetized planets of the outer Solar System produce kilometric radio emissions at very low frequencies (<1 ${< } 1\,$MHz). They reveal the planetary magnetic dynamics and their interaction with the solar wind. Those radio emissions can also serve as a proxy for interplanetary space weather monitoring.
E. Rouillé, B. Cecconi, B. Segret, J. N. Girard, A. Loh   +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

Frequency Standard Contributions to Limitations on the Signal‐to‐Noise Ratio in Very Long Baseline Interferometric Observations

Radio Science, Volume 61, Issue 6, June 2026.
Abstract Since its observation in 2019, the first image of a super‐massive black hole using Very Long Baseline Interferometry (VLBI) with an Earth‐scale baseline has generated much scientific and public interest. Work is now underway to extend the baseline into space to obtain higher image resolution.
E. A. Burt, T. A. Ely, G. C. Bower, T. J. W. Lazio, M. Anderson, S. Hernandez   +5 more
wiley   +1 more source

New Constraints on the Jovian Narrowband Radio Components From Juno/Waves Observations and 3D Geometrical Simulations

Journal of Geophysical Research: Space Physics, Volume 131, Issue 4, April 2026.
Abstract Measurements of Waves instrument onboard the Juno spacecraft suggest that narrowband kilometric radiation (nKOM; 20–141 kHz) and narrowband low‐frequency radiation (nLF; 5–70 kHz) are generated within the plasma near the Io plasma torus (IPT) in low‐latitude regions.
A. Boudouma, P. Zarka, C. K. Louis, M. Imai, C. Briand   +4 more
wiley   +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

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

Maser Investigation toward Off-Plane Stars (MIOPS): Detection of SiO Masers in the Galactic Thick Disk and Halo

The Astrophysical Journal
Studying stars that are located off the Galactic plane is important for understanding the formation history of the Milky Way. We searched for SiO masers toward off-plane O-rich asymptotic giant branch (AGB) stars from the catalog presented by Mauron et ...
Wenjin Yang, Yuanwei Wu, Yan Gong, Nicolas Mauron, Bo Zhang, Karl M. Menten, Xiaofeng Mai, Dejian Liu, Juan Li, Jingjing Li   +9 more
doaj   +1 more source

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