Abstract Details
| Name: Mayank Rajput Affiliation: National Institute of Technology, Rourkela, Odisha Conference ID: ASI2025_544 Title : Metric Type II Radio Emission associated with Coronal Mass Ejections of Large Angular Widths: Some New Insights Authors and Co-Authors : Mayank Rajput1, Susanta Kumar Bisoi1, P. Janardhan2 Abstract Type : Poster Abstract Category : Sun, Solar System, Exoplanets, and Astrobiology Abstract : Coronal Mass Ejection (CME) driven shocks can accelerate charged particles up to relativistic speeds, producing Type II solar radio bursts. The CME directly impacts Earth, so studying them becomes important from a space weather perspective. Due to the association of Type II bursts with CME, it is important to study them and the correlation of different properties of Type II with that of the CME. This study analyzed a correlation between the frequency bandwidth of Type II radio bursts in the frequency range 127–20 MHz, obtained from an e-CALLISTO spectrograph, and the angular width of the associated CMEs. To obtain the true angular width of the CMEs, we used a forward-fitting model known as the Graduated Cylindrical Shell model. The dynamic spectrum obtained from e-CALLISTO was used to calculate the frequency bandwidth of the Type II bursts. Our investigation found that the frequency bandwidth of Type II bursts is anti-correlated with the angular width of the associated CMEs with a correlation coefficient of ~74%, indicating that the CMEs with large angular width can produce narrow-band Type II emissions. This starkly contrasts a recent report that the CMEs with large angular widths produce broad-band Type II emission. To locate the Type II radio burst to CME-driven shock front, we further estimated the Type II burst height at the burst-onset time and compared it with the deduced height of the associated CMEs/shocks. For all of the Type II burst events, it was found that the height of the Type II burst was less than the CME height, indicating that the Type II emissions are produced in the flank region of the CME-driven shock. This suggests there could be narrow-band Type II emission as the condition for generating Type II bursts satisfies in a narrower region in the flank of the CMEs. |