Dynamical Motions and Oscillations of a Quiescent Prominence Observed by IRIS and SDO/AIA

We studied the dynamical properties of a quiescent prominence using high-resolution observations provided by the Interface Region Imaging Spectroscopy (IRIS) and Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). IRIS's spectroscopic observations helped us compute the Doppler velocity maps in the prominence. The emission measure and temperature maps in the prominence regions are computed using the Differential Emission Measure (DEM) analysis of the EUV observations obtained from SDO/AIA. We employed the local correlation tracking (LCT) to find the plane-of-sky motion in the prominence. The prominence bubble was found to be rotating anti-clockwise with a rotation period of around 60 minutes when viewed from the top of it. We found dynamical motion 20 to 60 km s-1 in the prominence and its rotations. On the other hand, the central part of the prominence was making torsional rotations. This could be associated with upward propagating torsional Alfv\'en waves along the magnetic field lines. We also found a sizable helical motion in the upper part of the prominence with a linear speed of 6.35 km s-1. Further, the prominence was found to have significant oscillations in the frequency band 1.5 - 2.5 mHz, corresponding to the period range of 7 - 11 minutes with a dominant oscillation for around 10 minutes.