Abstract Details
| Name: | Sasikumar Raja Kantepalli |
| Affiliation: | Indian Institute of Astrophysics, Bengaluru |
| Conference ID : | ASI2024_976 |
| Title : | Spectral Analysis of Solar Radio Type III Bursts from 20 kHz to 410 MHz |
| Authors : | K. Sasikumar Raja1,2, Milan Maksimovic1, Eduard P. Kontar3, Xavier Bonnin1, Philippe Zarka1,4, Laurent Lamy1,4,5, Hamish Reid6, Nicole Vilmer1,4, Alain Lecacheux1, Vratislav Krupar7,8, Baptiste Cecconi1,4, Lahmiti Nora1, Laurent Denis4 1 LESIA, Observatoire de Paris, Université PSL, Sorbonne Université, Université de Paris, CNRS, 92190 Meudon, France; 2 Indian Institute of Astrophysics, II Block, Koramangala, Bangalore-560 034, India 3 School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK 4 Unité scientifique de Nançay, Observatoire de Paris, CNRS, PSL, Université d’Orléans/OSUC, Nançay, France 5 Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France 6 Department of Space & Climate Physics, University College London, London, UK 7 Goddard Planetary Heliophysics Institute, University of Maryland, Baltimore County, Baltimore, MD 21250, USA 8 Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA |
| Authors Affiliation: | We present the statistical analysis of the spectral response of solar radio type III bursts over the wide frequency range between 20 kHz and 410 MHz. For this purpose, we have used observations that were carried out using both spaced-based (Wind/Waves) and ground-based (Nan\c{c}ay Decameter Array and Nan\c{c}ay Radioheliograph) facilities. In order to compare the flux densities observed by the different instruments, we have calibrated the data and converted them to Solar Flux Units. This study found that type III bursts observed in the metric to hectometric wavelength range statistically exhibit a clear maximum radio flux density at around 2 MHz. In addition, using a simple empirical model we show that the median radio flux `S' of the studied dataset obeys the polynomial form $Y = 0.0497*x^3 - 1.6352*x^2 + 16.3033*x - 41.2399$, with $X=\ln{(F_\text{kHz})}$ and with $Y=\ln{(S_\text{SFU})}$. Using the Sittler and Guhathakurtha model for coronal streamers we have found that maximum of radio power falls in the range 4 to 10 $R_{\odot}$, depending on whether the type III emissions are assumed to be at the fundamental or the harmonic. |
| Mode of Presentation: | Poster |
| Abstract Category : | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract : | We present the statistical analysis of the spectral response of solar radio type III bursts over the wide frequency range between 20 kHz and 410 MHz. For this purpose, we have used observations that were carried out using both spaced-based (Wind/Waves) and ground-based (Nan\c{c}ay Decameter Array and Nan\c{c}ay Radioheliograph) facilities. In order to compare the flux densities observed by the different instruments, we have calibrated the data and converted them to Solar Flux Units. This study found that type III bursts observed in the metric to hectometric wavelength range statistically exhibit a clear maximum radio flux density at around 2 MHz. In addition, using a simple empirical model we show that the median radio flux `S' of the studied dataset obeys the polynomial form $Y = 0.0497*x^3 - 1.6352*x^2 + 16.3033*x - 41.2399$, with $X=\ln{(F_\text{kHz})}$ and with $Y=\ln{(S_\text{SFU})}$. Using the Sittler and Guhathakurtha model for coronal streamers we have found that maximum of radio power falls in the range 4 to 10 $R_{\odot}$, depending on whether the type III emissions are assumed to be at the fundamental or the harmonic. |