Multi-thermal Structure of Solar Jets based on Combined EUV and Ha Observations

RESUMO

This study investigates the multi-thermal structure of solar jets by combining extreme ultra-violet (EUV) and Ha observations, addressing whether cool and hot components originate from the same jet, their morphological similarities and differences, and the role of mini-filaments. We analyze 70 jet events simultaneously observed by Atmospheric Imaging Assembly (AIA) and Chinese Ha Solar Explorer (CHASE) from 2023 May 25 to 2026 January 15. The events are classified into four types based on whether or not there are significant differences between the two wavebands in terms of length and width; nonlinear force-free field extrapolations are applied to examine magnetic fields. We find that the cool and hot components correspond to different temperature parts of a unified jet, showing spatiotemporal coincidence and kinematic synchronization. Morphologically, 30% show no significant difference in length/width, 37% differ in one dimension, and 33% differ in both. About 80% involve mini-filament eruptions; jets with filaments more often exhibit morphological differences (filament non-expansion, hot shell thickness, insufficient kinetic energy, or material rarefaction). In contrast, jets without filaments tend to show consistent morphologies; when discrepancies occur, they are mainly linked to small magnetic field curvature, which reduces magnetic tension and leads to less acceleration of cool material. These results highlight the complex interaction between thermal, dynamic, and magnetic factors in shaping jet morphology.