Fast Magnetosonic Waves and Flows in a Solar Prominence Foot: Observations and Modeling

TL;DR

This study combines high-resolution solar observations and 2.5D MHD modeling to analyze fast magnetosonic waves and flows in a solar prominence foot, revealing wave properties, magnetic field estimates, and dynamic behaviors.

Contribution

It provides new observational evidence and modeling insights into nonlinear fast magnetosonic waves and flows in prominence feet, enhancing understanding of their fine-scale dynamics.

Findings

Waves have periods of 5-11 minutes and wavelengths around 2000 km.

Flows in threads have speeds of 16-46 km/s.

Magnetic field strength estimated between 5-17 G.

Abstract

We study recent observations of propagating fluctuations in a prominence foot with Hinode Solar Optical Telescope (SOT) high-resolution observations in Ca~II and H alpha emission which we identify as nonlinear fast magnetosnic waves. Here we analyze further the observations of propagating waves and flows with Interface Region Imaging Spectrograph (IRIS) Mg~II slit jaw images, in addition to Hinode/SOT Ca~II images. We find that the waves have typical periods in the range of 5 - 11 minutes and wavelengths in the plane of the sky (POS) of about 2000 km, while the flows in narrow threads have typical speed in the POS of ~16-46 km/s. We also detect apparent kink oscillations in the threads with flowing material, and apply coronal seismology to estimate the magnetic field strength in the range 5-17 G. Using 2.5D MHD we model the combined effects of nonlinear waves and flows on the observed dynamics of the prominence material, and reproduce the propagating and refracting fast magnetosonic waves, as well as standing kink-mode waves in flowing material along the magnetic field. The modeling results are in good qualitative agreements with the observations of the various waves and flows in the prominence foot, further confirming coronal seismology analysis and improving the understanding of the fine scale dynamics of the prominence material.