Speaker
Description
First Name: Souvik
Last Name: Bose
Affiliation: SETI/RoCS/UiO
All Authors: A. Sainz Dalda, S. Tiwari, V. Hansteen and B. De Pontieu
Abstract: At the interface between the Sun’s million-degree corona and its surface lies the chromosphere: cooler and far denser than the corona, yet it processes essentially all of the magnetoconvective energy that ultimately powers the outer atmosphere. How and where that energy is converted into heat remains a central open question in astrophysics. In this talk, I utilize high-resolution observations from IRIS, Hinode, and SDO, along with a state-of-the-art 3D radiative-MHD simulation, to argue that the key sites of energy release in active-region plage are not the familiar strong-field cores, but rather their magnetic edges. Machine-learning-assisted chromospheric inversions (IRIS2+) show that radiative losses per unit magnetic flux sharply peak in weak-to-intermediate fields at the expanding rims of plage flux tubes, while kG cores are relatively “dark,” carrying most of the flux but contributing only a minor fraction of the losses. The simulations reproduce this pattern and point to magnetic geometry—rather than field strength alone—as the primary control on atmospheric heating. I will place these results within the broader context of coronal-heating theories and outline how future coordinated campaigns with MUSE, Solar-C, and ground-based observatories can leverage this edge-dominated picture to probe the fundamental physics of chromospheric and coronal energy conversion.