Multilevel Observations of the Oscillations in the First Active Region of the New Cycle

TL;DR

This study presents multi-layer observations of oscillation dynamics in a solar facula from its formation to decay, revealing how low-frequency oscillations relate across different solar atmospheric layers and correlate with coronal structures.

Contribution

First multi-wave observational analysis of oscillations in a solar facula throughout its evolution, linking low-frequency oscillations across atmospheric layers and coronal structures.

Findings

Low-frequency oscillations (1-2 mHz) are concentrated in the facula's center during early stages.

Oscillations in the lower atmosphere are connected to those in the transition region and corona.

Oscillation patterns evolve with the facula, reflecting changes in magnetic and atmospheric structure.

Abstract

For the first time, a multi-wave research of oscillation dynamics in a solar facula from its birth to decay was carried out. We performed spectral observations of active region NOAA 12744 at Horizontal Solar Telescope of the Sayan Solar Observatory in the H$\alpha$, He I 10830 A, and Si I 10827 A lines. We used Solar Dynamics Observatory (SDO) line-of-sight magnetic field data and the 1600 A, 304 A, and 171 A UV channels. At the early stages of the facula evolution, we observed low-frequency (1-2 mHz) oscillations concentrate in the central part of the facula. In the lower solar atmosphere, this is registered in the intensity, line-of-sight velocity, and magnetic field signals. These frequencies were also observed in the transition region and corona (304 A and 171 A channels). At the maximal development phase of the facula evolution, the low frequency oscillations closely reproduce the coronal loop structures forming above the active region. At the decay phase, the spatial distributions of the observed frequencies resemble those found in and above the undisturbed chromosphere network. Our results indicate a direct relation of the low frequency oscillations observed in the lower solar atmosphere with the oscillations in the coronal loops, which is probably implemented through the loop footpoints.