Solar/Stellar Atmospheric Tomography with mm-radio Snapshot Spectroscopic Imaging

Abstract

Millimeter (mm) frequencies are primarily sensitive to thermal emission from layers across the stellar chromosphere up to the transition region, while metre-wave (radio) frequencies probe the coronal heights. Together the mm and radio band spectroscopic snapshot imaging enables the tomographic exploration of the active atmospheric layers of the cool main-sequence stars (spectral type: FGKM), including our Sun. Sensitive modern mm and radio interferometers let us explore solar/stellar activity covering a range of energy scales at sub-second and sub-MHz resolution over wide operational bandwidths. The superior uv-coverage of these instruments facilitate high dynamic range imaging, letting us explore the morphological evolution of even energetically weak events on the Sun at fine spectro-temporal cadence. This article will introduce the current advancements, the data analysis challenges and available tools. The impact of these tools and novel data in field of solar/stellar research will be summarised with future prospects.