Affiliation

Astronomical Institute Slovak Academy of Sciences

Main category

Natural Sciences (Astrophysics and Astrononmy)

Abstract

We aim to study the evolution of an arch filament system (AFS) and of its individual arch filaments to learn about the processes occurring in them. We observed the AFS at the GREGOR solar telescope on Tenerife at high cadence with the very fast spectroscopic mode of the GREGOR Infrared Spectrograph (GRIS) in the He I 10830 Å spectral range. The He I triplet line profiles were fit with analytical functions to infer line-of-sight (LOS) velocities to follow the plasma motions within the AFS. We tracked the temporal evolution of an individual arch filament over its entire lifetime as seen with the He I 10830 Å triplet. The studied individual arch filament expands in height and extends in length (from 13” to 21”). The lifetime of this arch filament is about 30 min. About 11~min after the arch filament is seen in He I, the loop top starts to rise with an average LOS velocity of 6 kms-1. Only two minutes later, plasma drains down with supersonic velocities towards the footpoints reaching peaks up to 40 kms-1 in the chromosphere. The temporal evolution of He I 10830 Å profiles near the leading pore showed almost ubiquitous dual red components of the He I triplet, indicating strong downflows, along with material nearly at rest within the same resolution element during the whole observing time. We follow the arch filament as it carries plasma during its rise from the photosphere to the corona. The material then drains toward the photosphere, reaching supersonic velocities, along the legs of the arch filament. Our observational results support theoretical AFS models and will serve to improve future models. The consequences of observations such as AFS for EST will be deduced. Also recommendations about EST performance and its instrumentation will be presented.

Conference

EST2018

Link this presentation

https://science-media.org/presentation/332