TIME RADIO TYPE III RAFAGA TIME PROFILE STUDY Using Parker’s Solar Research by Tulsi Thapa and Yihua Yan-Comunity of European Astronomers Radio

Type III radio explosions are frequent and powerful radio emissions caused by electron beams that travel through the solar crown to the interplanetary environment, providing valuable information about the solar magnetic fields and the dynamics of the solar wind. These bursts are associated with solar flares and indirectly indicate an energy electron that moves along the magnetic field lines. This study uses the data of the Parker solar probe to examine the time profile characteristics of type III bursts in the low frequency domain in different frequency bands, including its increases in increase, peak and decomposition. We have selected 43 Ráfagas Type III well defined, ensuring that they were isolated and free of interference and time profiles were characterized using a Bi-Gaussian adjustment approach. We investigate the dependencies of these temporary features of the frequency and obtain ideas about explosion speeds, bandwidths and drift rates to understand the underlying physical mechanisms that govern the dynamics of type III explosion, with the aim of closing gaps to understand its characteristics temporal and spectral.

Independence of the frequency of time asymmetry

Recent studies, especially for Chrysaphi et al. (2024)They have underlined the independent nature of the frequency of the asymmetry of the time profile in the explosions of Type III radio. This discovery is fundamental, since it emphasizes that the physical mechanisms responsible for the generation and spread of these explosions work uniformly at several frequencies.

Time profile asymmetry, quantified by the decomposition time ratio to increase time (t_d/t_Kidney), resulted in a spectral index of 0.12 ± 0.19. This value close to zero indicates that the asymmetry of time observed is minimally influenced by frequency variations. Consequently, this suggests that internal processes within the solar crown and the interplanetary environment, which affect type III explosions, maintain consistent characteristics regardless of the frequency.

Correlation with the duration of the explosion

An exhaustive analysis of the duration of the explosion with respect to its increase, peak and phases of decomposition revealed significant correlations, particularly with the decomposition time. A strong correlation (CC = 0.95) was found between the duration of the explosion and the decomposition time, indicating that the decomposition phase plays a crucial role in determining the general duration of type III explosions. The additional exam showed substantial correlations between the duration of the explosion and the increase time (CC = 0.75) and between the duration of the explosion and the peak time (CC = 0.76).

Figure 1: The panels show the asymmetry time profile (TD/TR) depending on the frequency. The continuous red lines represent the adjustment of the power law with its corresponding spectral values ​​shown within the panel. The panel (b), (c) and (d) are the dispersion graphs for the increase, the peak and the decomposition time depending on the duration of the explosion, respectively. The size of the Magenta bar represents the standard errors derived from the less square setting of the data; Blue discontinua lines are the best tight regression lines.

These correlations highlight that the first phases of the explosion, including the increase and peak hours, are fundamental to shape the total duration of the event. Significant correlations with the increase and peak times further emphasize the role of the initial explosion dynamics in the general duration configuration. These early stages are crucial to establish the conditions for the evolution of the subsequent explosion, influenced by factors such as the speed of the electron beam, density fluctuations and magnetic field structures.

Conclusion

In conclusion, this study has thrown new light on temporary profiles and underlying physical mechanisms of type III radio explosions. The discovery of time asymmetry independent of frequency and strong correlations between the duration of the explosion and the decomposition phase underlines the complex dynamics of electron beams and their interactions with plasma. These findings significantly affect our understanding of solar-terrestrial interactions and the fundamental processes that govern the solar crown and interplanetary space, contributing to a deeper understanding of the intricate relations between the sun and our planet.

Based on the recent article by Thapa T. and Yan Y., (2024), Study of time profile of Radio Solar III radio using Parker Solar Probe, APJ, 972, 2, doi:10.3847/1538-4357/AD5E77

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