Date of upload:
21.10.2015
Co-author:
D. Utz, J. Rybák
Abstract:
We studied spectroscopic signatures of potential means of energy transport into the chromosphere by investigating temporal variations of the width, the intensity and the Dopplershift of the Hα spectral line profile observed by the tunable Lyot filter installed on the Dutch Open Telescope. Furthermore, we studied co-spatial chromospheric and photospheric structures with a likelihood of being causally connected to the variations of these spectroscopic signatures. We found oscillations in the intensity and Doppler velocities, while the width of the Hα spectral line profile produced no discernible periodicity. Moreover, the amplitude of the intensity is lagging behind the Doppler velocities. We interpret our findings as signatures of magneto-acoustic wave propagation. The investigation of the likely source of the observed oscillations directed our attention to bright chromospheric mottles. Subsequently, we studied the possible relation of their appearance wit h a co-spatial long-living and dynamically evolving group of G-band bright points (GBPs). According to our findings we propose a causal relation between the dynamical evolution of the group of GBPs and the appearance of bright mottles in the region above them.