Juie Shetye, Ms. - PhD
Armagh Observatory, Armagh, UK
http://star.arm.ac.uk/staff/jus.html
       
       
Session 2 - Poster

Analysis of apparent ultra-fast spicules using high resolution ground-based data

J. Shetye (Armagh Observatory), J. G. Doyle (Armagh Observatory), E. Scullion (Trinity College Dublin), C. Nelson (University of Sheffield)
       

A statistical study of spectral images, taken from the CRISP instrument at the Swedish 1-m Solar Telescope in H-alpha 656.28 nm of fast spicules, present Doppler velocities in the range of -41km/s to +41 km/s. Remarkably, many of these spicules display apparent velocities above 500 km/s, with very short lifetimes of up to 20 s and apparent lengths of around 3500 km. Here we present, the other spectral properties of these events in the line scan. One result is that they are repetitive i.e. appear at the same location but they are not co-temporal or necessarily periodic in nature. In 89 % of the cases there is temporal offset by 3.7 s to 5 s. We interpret the observations as mass motions that appear in the field-of-view of CRISP’s 0.0060 nm filters in the line of sight, along their projection. We observed that 30% of the features showed repetitions at same location. This confirms that these are in fact, elongated mass motions rather than so called sheets, fast spicules or fibrils. Further we observed lateral motion which could be related to waves. With DKIST VTF instrument, having 3 times more spatial resolution than CRISP and much higher temporal resolution, we can being to understand the nature of such fine-scale transient phenomena in greater details.