Abstract:
Coronal rain is one of the highest resolution tracers of the coronal magnetic field. In this work the dynamics of a prominence/coronal rain complex are analysed based on spectroscopic and imaging observations with IRIS, Hinode/SOT and SDO/AIA. The loop-like magnetic field arcade hosting the rain is observed to slowly expand in height. Prior and especially during this movement, several (~100) small (~1 arcsec) and short (<20 sec) bursts of plasma perpendicular to the loop arcade are captured in the Si IV and Mg II lines. The line profiles are broad and asymmetric with long tails above ~100 km/s. These microjets are accompanied with strong intensity enhancements co-spatially and along the loop in most of the AIA channels, indicating significant energy release increasing the temperature to several MK. Some events generate transverse MHD waves and the strongest events are accompanied by ejection of plasmoid-like structures. We interpret these microjets as reconnection outflows, produced by component reconnection as the magnetic structure expands transversely. The originally cold conditions of the rain allows in this case a unique high resolution glance at the reconnection dynamics in low beta plasmas.