An In Situ Interplanetary “U-burst”: Observation and Results

0539563 - ÚFA 2021 RIV US eng J - Článek v odborném periodiku
Oliveros, J.C.M. - Castillo, S.M.D. - Krupař, Vratislav - Pulupa, M. - Bale, S. D. - Calvo-Mozo, B.
An In Situ Interplanetary “U-burst”: Observation and Results.
Astrophysical Journal. Roč. 897, č. 2 (2020), č. článku 170. ISSN 0004-637X. E-ISSN 1538-4357
Grant CEP: GA ČR(CZ) GJ17-06818Y
Institucionální podpora: RVO:68378289
Klíčová slova: Radio Bursts * Electrostatic Waves * Interplanetary Medium * Solar coronal mass ejections
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 5.877, rok: 2020
Způsob publikování: Open access
http://arxiv.org/pdf/1910.04306

We report and examine the observation of an unusual and rare in situ electron observation associated with a solar type III radio burst on 1996 December 24. This radio event was accompanied by high-energy electrons, measured by the Solid State Telescope on board the Wind spacecraft. The type III radio emission started at 13:10 UTC and was associated with a C2.1 GOES-class flare whose maximum was at 13:11 UTC and hosted by the active region NOAA 8007/8004, located on the west limb at N05 degrees W74 degrees/N06 degrees W85 degrees. During this event, the observation of an electron energy distribution likely to be associated with the radio emission was registered. The electrons arrive at the spacecraft predominantly from the antisolar direction, suggesting that their general motion is sunward along a closed magnetic field line. Leblanc et al. propose a model in which energetic electrons are injected into a coronal flux tube at one of its footpoints, releasing standard type-III emission. As the magnetic field then directs them back toward the magnetic-conjugate footpoint of the first, the electrons release subsequent emission whose radio profile is a quasi-time reversal of the standard. We have constructed a cylindrical flux rope facsimile of this scenario that reproduces the U-burst profiles. We also report observational features indicating a secondary electron energy distribution and propose a scenario that explains this feature.
Trvalý link: http://hdl.handle.net/11104/0317335