Iranian Journal of Geophysics

Iranian Journal of Geophysics

Fluctuating morphology of the solar magnetic bright points

Document Type : Research Article

Authors
Ehsan Tavabi 1
Sima Zeighami 2
1 Associate Professor, Physics Department, Payame Noor University (PNU), Tehran, Iran
2 Assistant Professor, Department of Physics, Tabriz Branch, Islamic Azad University, Tabriz, Iran
10.30499/ijg.2024.455744.1600
Abstract
The solar corona has a temperature equivalent to one million degrees Kelvin. The very high temperature of this region indicates that this region is heated to this extent by a source other than the heat emitted from the photosphere. It is thought that the energy required to heat the solar corona is provided by the very turbulent flows of the convection layer located below the photosphere, which is proposed to explain how the two types of mechanisms are different. The first mechanism includes wave heating and describes the formation of sound waves, gravity waves and magnetic hydrodynamic waves due to the presence of turbulent and turbulent currents. After being produced, these waves go up and when they hit the solar corona, they disintegrate and release energy in the form of thermal energy. The second mechanism includes magnetic heating, in which magnetic energy is continuously created by the currents in the photosphere and is released towards magnetic regions and sunspots in the form of flares and huge solar flares. In this research, using the time series taken by the IRIS telescope, different regions of the solar disk in 4 filters C II, Si IV, Mg II h and k (1330, 1400, 2796 and 2832 Å) are investigated. The morphology and displacement of magnetic bright points can be described as convective turbulence caused by super-granular flows from the center to the edge. The purpose of this research is to find out the fluctuating morphology of the bright points in the border regions of the network and inside the network. The intensity-time graphs clearly show the coherence of the fluctuations, which is because of the common origin of these fluctuations, which are created with similar periods. Also, the wavelet analysis of intensity fluctuations showed that the frequency of fluctuations is from 2.5 to 12 minutes. Also, to investigate the wave propagation in these layers, the correlation between the chromosphere and the transition region was investigated. Due to the difference in the height of the chromosphere layer and the transition region, and the time delay obtained from the intensity fluctuations between the two mentioned layers, the wave speed was determined with an approximate value of 150 km  s-1. Examining the captured images shows that their source lies in the bright points of the chromosphere. Many jets reach a temperature of at least 105 K and form an important part of the transition region structure. They are likely an intermittent but continuous source of mass and energy for the solar wind.
Keywords
The Sun
chromosphere
network and internetwork bright points
wave speed

Subjects

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Iranian Journal of Geophysics
Volume 19, Issue 2
May and June 2025
Pages 1-11