3He-rich solar energetic particles from sunspot jets
Solar sources of suprathermal (<1 MeV nucleon−1) 3He-rich solar energetic particles (SEPs) have been commonly associated with jets originating in small, compact active regions at the periphery of near-equatorial coronal holes. Sources of relatively rare, high-energy (>10 MeV nucleon−1) 3He-ric...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2018 |
| País: | España |
| Institución: | Universidad de Alcalá (UAH) |
| Repositorio: | e_Buah Biblioteca Digital Universidad de Alcalá |
| Idioma: | inglés |
| OAI Identifier: | oai:ebuah.uah.es:10017/60417 |
| Acceso en línea: | http://hdl.handle.net/10017/60417 https://dx.doi.org/10.3847/2041-8213/aaf37f |
| Access Level: | acceso abierto |
| Palabra clave: | Acceleration of particles Sun: flares Sun: magnetic fields Sun: particle emission Sun: abundances Física Astronomía Physics Astronomy |
| Sumario: | Solar sources of suprathermal (<1 MeV nucleon−1) 3He-rich solar energetic particles (SEPs) have been commonly associated with jets originating in small, compact active regions at the periphery of near-equatorial coronal holes. Sources of relatively rare, high-energy (>10 MeV nucleon−1) 3He-rich SEPs remain unexplored. Here we present two of the most intense 3He-rich (3He/4He > 1) SEP events of the current solar cycle 24 measured on the Advanced Composition Explorer at energy >10 MeV nucleon−1. Although 3He shows high intensities, Z > 2 ions are below the detection threshold. The events are accompanied by type-III radio bursts, but no type-II emission as typically seen for suprathermal 3He-rich SEPs. The corresponding solar sources were analyzed using high-resolution, extreme-ultraviolet imaging and photospheric magnetic field observations on the Solar Dynamics Observatory. We find the sources of these events associated with jets originating at the boundary of large sunspots with complex βγδ magnetic configuration. Thus, details of the underlying photospheric field apparently are important to produce 3He to high energies in the examined events. |
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