Figura: Rappresentazione delle onde osservate nella corona solare nell'estremo-ultravioletto (EUV).
Dr. Spiro Kosta Antiochos “The Origins of the Solar Corona's Self-Organization.”
Mercoledì 27 Marzo 2024, ore 14.30 – Sala Seminari Villa Magliola INAF-OATo
SEGUI IL SEMINARIO IN STREAMING
Abstract
The solar corona is an amazing example of the self-organization of a complex system.
The magnetic field in the corona is due to the flux at the photosphere, which has enormous structure, consisting of many bipolar sources that are constantly emerging and cancelling.
Furthermore, this magnetic field is continuously driven by the photospheric convective motions that are fully turbulent and have structure at many scales.
In spite of this complexity, the coronal field is generally observed to be close a minimum-energy potential (current-free) state, except for certain very specific locations observed as filaments/prominences.
We argue that this self-organization is the fundamental origin of the corona’s ubiquitous explosive activity including CMEs, flares, and jets.
We show how chaotic reconnection in the corona, coupled with the conservation of magnetic helicity leads to the observed coronal structure.
Furthermore, we show that these processes are the origin of both the explosive and quasi-steady activity observed in the corona.
Since reconnection and helicity conservation are generic processes, our results should be relevant to many astrophysical phenomena.
