Details

Autor(en) / Beteiligte

• Mohan, Atul

Titel

Discovery of Correlated Evolution in Solar Noise Storm Source Parameters: Insights on Magnetic Field Dynamics during a Microflare

Ist Teil von

• Astrophysical journal. Letters, 2021-03, Vol.909 (1), p.L1

Ort / Verlag

Austin: The American Astronomical Society

Erscheinungsjahr

2021

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Abstract A solar type-I noise storm is produced by accelerated particle beams generated at active regions undergoing magnetic field restructuring. Their intensity varies by orders of magnitude within subsecond and sub-MHz scales. But the morphological evolution of these sources is not studied at these scales due to the lack of required imaging cadence and fidelity in meterwave bands. Using data from the Murchison Widefield Array, this work explores the coevolution of size, sky-orientation, and intensity of a noise storm source associated with a weak microflare. This work presents the discovery of two correlated modes of evolution in the source parameters: a sausage like “S” mode where the source intensity and size show an anticorrelated evolution; and a torsional like “T” mode where the source size and sky-orientation show a correlated evolution. A flare mediated mode conversion is observed from “T” to “S” for the first time in these sources. These results support the idea of build up of magnetic stress energy in braided active region loops, which later become unstable causing flares and particle acceleration until they relax to a minimally braided state. The discovered mode conversion can be a future diagnostic for such events.