First Radio Evidence for Impulsive Heating Contribution to the Quiet Solar Corona

• Published in: Astrophysical journal. Letters 2020-06, Vol.895 (2), p.L39
• Main Authors: Mondal, Surajit, Oberoi, Divya, Mohan, Atul
• Format: Article
• Language: English
• Subjects: Clustering; Corona; Coronal heating; Emissions; Heating; Heating requirements; Histograms; Occupancy; Quiet solar corona; Quiet Sun; Solar corona; Solar coronal heating; Solar coronal radio emission; Solar probes
• ISSN: 2041-8205; 2041-8213
• DOI: 10.3847/2041-8213/ab8817

This Letter explores the relevance of nanoflare-based models for heating the quiet Sun corona. Using meterwave data from the Murchison Widefield Array, we present the first successful detection of impulsive emissions down to flux densities of ∼mSFU, about two orders of magnitude weaker than earlier attempts. These impulsive emissions have durations 1 s and are present throughout the quiet solar corona. The fractional time occupancy of these impulsive emissions at a given region is 10%. The histograms of these impulsive emissions follow a power-law distribution and show signs of clustering at small timescales. Our estimate of the energy that must be dumped in the corona to generate these impulsive emissions is consistent with the coronal heating requirements. Additionally, the statistical properties of these impulsive emissions are very similar to those recently determined for magnetic switchbacks by the Parker Solar Probe (PSP). We hope that this work will lead to a renewed interest in relating these weak impulsive emissions to the energy deposited in the corona, the quantity of physical interest from a coronal heating perspective, and explore their relationship with the magnetic switchbacks observed by the PSP.