1. Loss-cone instability modulation due to a magnetohydrodynamic sausage mode oscillation in the solar corona
- Author
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Laura A. Hayes, Warren Shelley, Peter T. Gallagher, Eoin P. Carley, Diana E. Morosan, Nicole Vilmer, Sophie A. Murray, Trinity College Dublin, Dublin Institute for Advanced Studies (DIAS), NASA Goddard Space Flight Center (GSFC), University of Helsinki, Boston University [Boston] (BU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), French Program on Solar-Terrestrial Physics of INSU (PNST, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Space Physics Research Group, Particle Physics and Astrophysics, and Department of Physics
- Subjects
0301 basic medicine ,Astrophysical plasmas ,Science ,Astrophysics::High Energy Astrophysical Phenomena ,General Physics and Astronomy ,02 engineering and technology ,Instability ,114 Physical sciences ,Magnetically confined plasmas ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,CYCLOTRON MASER INSTABILITY ,RADIO PULSATIONS ,Physics::Plasma Physics ,ABSORPTION ,BURSTS ,TRANSITION-REGION ,Astrophysics::Solar and Stellar Astrophysics ,PLASMA RADIATION ,Magnetohydrodynamic drive ,lcsh:Science ,Computer Science::Databases ,Physics ,Solar physics ,Multidisciplinary ,Solar flare ,Oscillation ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,SIGNATURE ,Magnetic reconnection ,General Chemistry ,Plasma ,021001 nanoscience & nanotechnology ,115 Astronomy, Space science ,Computational physics ,ELECTRONS ,030104 developmental biology ,13. Climate action ,Physics::Space Physics ,lcsh:Q ,Magnetohydrodynamics ,INJECTION ,0210 nano-technology ,EMISSION ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
Solar flares often involve the acceleration of particles to relativistic energies and the generation of high-intensity bursts of radio emission. In some cases, the radio bursts can show periodic or quasiperiodic intensity pulsations. However, precisely how these pulsations are generated is still subject to debate. Prominent theories employ mechanisms such as periodic magnetic reconnection, magnetohydrodynamic (MHD) oscillations, or some combination of both. Here we report on high-cadence (0.25 s) radio imaging of a 228 MHz radio source pulsating with a period of 2.3 s during a solar flare on 2014-April-18. The pulsating source is due to an MHD sausage mode oscillation periodically triggering electron acceleration in the corona. The periodic electron acceleration results in the modulation of a loss-cone instability, ultimately resulting in pulsating plasma emission. The results show that a complex combination of MHD oscillations and plasma instability modulation can lead to pulsating radio emission in astrophysical environments., Magnetohydrodynamic (MHD) waves and plasma instabilities can be studied during solar flares. Here the authors show evidence for an MHD sausage mode oscillation periodically triggering electron acceleration at a magnetic null point in the solar corona, indicating MHD oscillations in plasma can indirectly lead to loss-cone instability modulation.
- Published
- 2019
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