LOFAR Observations of a Jet-driven Piston Shock in the Low Solar Corona

Abstract : The American Astronomical Society, find out more The American Astronomical Society, find out more The Institute of Physics, find out more The Institute of Physics, find out more LOFAR Observations of a Jet-driven Piston Shock in the Low Solar Corona Ciara A. Maguire1,2 , Eoin P. Carley2, Pietro Zucca3, Nicole Vilmer4,5, and Peter T. Gallagher2 Published 2021 March 1 • © 2021. The American Astronomical Society. All rights reserved. The Astrophysical Journal, Volume 909, Number 1 Citation Ciara A. Maguire et al 2021 ApJ 909 2 151 Total downloads Turn on MathJax Get permission to re-use this article Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Hide article information Author affiliations 1 School of Physics, Trinity College Dublin, Dublin 2, Ireland 2 Astronomy & Astrophysics Section, Dublin Institute for Advanced Studies, Dublin, D02 XF86, Ireland 3 ASTRON Netherlands Institute for Radio Astronomy, Dwingeloo, The Netherlands 4 LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universitès, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Citè, 5 place Jules Janssen, F-92195 Meudon, France 5 Station de Radioastronomie de Nançay, Observatoire de Paris, PSL Research University, CNRS, Univ. Orlèans, F-18330 Nançay, France ORCID iDs Ciara A. Maguire https://orcid.org/0000-0001-9564-6151 Eoin P. Carley https://orcid.org/0000-0002-6106-5292 Pietro Zucca https://orcid.org/0000-0002-6760-797X Nicole Vilmer https://orcid.org/0000-0002-6872-3630 Peter T. Gallagher https://orcid.org/0000-0001-9745-0400 Dates Received 2020 October 12 Revised 2021 January 2 Accepted 2021 January 6 Published 2021 March 1 Check for updates using Crossmark DOI https://doi.org/10.3847/1538-4357/abda51 Keywords Active solar corona; Solar radio emission; Shocks; Radio bursts; Plasma jets; Solar flares; Solar coronal streamers; Solar extreme ultraviolet emission Journal RSS Create or edit your corridor alerts What are corridors? This link opens in a new tab. Create citation alert Abstract The Sun produces highly dynamic and eruptive events that can drive shocks through the corona. These shocks can accelerate electrons, which result in plasma emission in the form of a type II radio burst. Despite the large number of type II radio burst observations, the precise origin of coronal shocks is still subject to investigation. Here, we present a well-observed solar eruptive event that occurred on 2015 October 16, focusing on a jet observed in the extreme ultraviolet by the Atmospheric Imaging Assembly (SDO/AIA), a streamer observed in white light by the Large Angle and Spectrometric Coronagraph (SOHO/LASCO), and a metric type II radio burst observed by the LOw Frequency Array (LOFAR). LOFAR interferometrically imaged the fundamental and harmonic sources of a type II radio burst and revealed that the sources did not appear to be cospatial, as would be expected from the plasma emission mechanism. We correct for the separation between the fundamental and harmonic using a model that accounts for scattering of radio waves by electron density fluctuations in a turbulent plasma. This allows us to show the type II radio sources were located ∼0.5R⊙ above the jet and propagated at a speed of ∼1000 km s−1, which was significantly faster than the jet speed of ∼200 km s−1. This suggests that the type II burst was generated by a piston shock driven by the jet in the low corona.