Oscillatory behavior of chromospheric fine structures in a network and a semi-active regions

TL;DR

This study investigates the oscillatory behaviors of chromospheric fine structures in a solar network and semi-active region using high-resolution H-alpha observations and wavelet analysis, revealing differences in their periodicities and phase relationships.

Contribution

It provides new insights into the oscillatory properties of chromospheric fine structures in different solar regions through detailed wavelet analysis of high-resolution spectral data.

Findings

Differences in oscillation periods between network and semi-active regions.

Distinct phase difference patterns indicating different wave propagation characteristics.

Identification of dominant oscillation frequencies in chromospheric fine structures.

Abstract

In the present work, we study the periodicities of oscillations in dark fine structures using observations of a network and a semi-active region close to the solar disk center. We simultaneously obtained spatially high resolution time series of white light images and narrow band images in the H$\alpha$ line using the 2D G\"ottingen spectrometer, which were based on two Fabry-Perot interferometers and mounted in the VTT/Observatorio del Teide/Tenerife. During the observations, the H$\alpha$ line was scanned at 18 wavelength positions with steps of 125 m\AA. We computed series of Doppler and intensity images by subtraction and addition of the H$\alpha$ $\pm$ 0.3 \AA\ and $\pm$ 0.7 \AA\ pairs, sampling the upper chromosphere and the upper photosphere, respectively. Then we obtained power, coherence and phase difference spectra by performing a wavelet analysis to the Doppler fluctuations. Here, we present comparative results of oscillatory properties of dark fine structures seen in a network and a semi-active region.