### The multi-thermal chromosphere: inversions of ALMA and IRIS data by J. M. da Silva Santos et al.

2020-02-18

Observations in the ultraviolet (UV) taken with the Interface Region Imaging Spectrograph (IRIS) have shown that the bright magnetic patches, known as plage, typically feature broader and brighter MgII h and k lines, which suggests that the chromosphere above plage is hotter and denser than in the quiet-Sun (e.g., Carlsson et al. 2015). However, not all line broadening is thermal; a nonthermal broadening component of up to 10 km s$^{-1}$ […]

### Evolution of Coronal and Interplanetary Shock Waves Inferred from a Radio Burst by Khaled Alielden

2020-02-04

Estimating the kinematics of Type II radio-burst sources, which are recognized as a shock waves, using electron-density models is inaccurate and restricted. In this article, a blast-expansion technique is used for the first time for estimating the kinematics of a Type II radio-burst source without using electron-density models by studying the density variation along the leading surface of the coronal mass ejections (CMEs) (herein: ejecta) during Type-II radio-burst emission. This […]