Band Splitting in m-Type II radio Bursts and their Role in Coronal Parameter Diagnostics
Abstract
Type II radio bursts are signatures of shock waves generated by solar eruptions, observed at radio wavelengths. While metric (m) type II bursts originate in the lower corona, their longer-wavelength (up to kilometers) counterparts extend into interplanetary space. A rare but valuable feature observed in some type II bursts is band splitting in their dynamic spectra, which provides crucial insights into physical parameters such as shock speed, Alfv\'en Mach number, Alfv\'en speed, and coronal magnetic field strength (B). In this study, we investigate band-splitting in 44 m-type II radio bursts observed by the Radio Solar Telescope Network during solar cycle 24 (2009 -- 2019). These events exhibit splitting in both fundamental and harmonic bands and are analyzed under both perpendicular and parallel shocks. All events are associated to solar flares and 41 (93 \%) with the coronal mass ejections. Shock speeds, derived using a hybrid coronal density model proposed by \cite{Vrsnak2004}, range from 350 to 1727 \kms. The relative bandwidth (BDW) of the split bands remains constant with frequency and height. Alfv\'en Mach numbers indicate moderate shock strength (1.06 -- 3.38), while Alfv\'en speeds and vary from 230 -- 1294 \kms\ and 0.48 -- 7.13 G, respectively. Power-law relationships are established as and , while the coronal magnetic field decreases with height as . These results enhance our understanding of shock dynamics and magnetic field structures in the solar corona.
Cite
@article{arxiv.2510.02821,
title = {Band Splitting in m-Type II radio Bursts and their Role in Coronal Parameter Diagnostics},
author = {Pooja Devi and Ramesh Chandra and Rositsa Miteva and M. Syed Ibrahim and Kamal Joshi},
journal= {arXiv preprint arXiv:2510.02821},
year = {2025}
}
Comments
14 Figures, 2 tables