Decimetric emission 500${}^{\prime \prime }$ away from a flaring Site: Possible scenarios from $\text{GMRT}$ solar radio observations

Abstract

We present a study of decimetric radio activity, using the first high time cadence (0.5 s) images from the $\text{Giant Meterwave Radio Telescope}$ ($\text{GMRT}$) at 610 MHz, associated with $\text{GOES}$ C1.4 and M1.0 class solar flares, and a coronal mass ejection (CME) onset that occurred on 20 June 2015. The high spatial resolution images from $\text{GMRT}$ show a strong radio source during the C1.4 flare, located ~500${}^{\prime \prime }$ away from the flaring site with no corresponding bright footpoints or coronal features nearby. In contrast, however, strong radio sources are found near the flaring site during the M1.0 flare and around the CME onset time. Weak radio sources, located near the flaring site, are also found during the maximum of the C1.4 flare activity, which show a temporal association with metric type III bursts identified by the Solar Broadband Radio Spectrometer at Yunnan Astronomical Observatory. Based on a multi-wavelength analysis and magnetic potential field source surface extrapolations, we suggest that the source electrons of $\text{GMRT}$ radio sources and metric type III bursts were originated from a common electron acceleration site. We also show that the strong $\text{GMRT}$ radio source is generated by a coherent emission process and its apparent location far from the flaring site is possibly due to the wave-ducting effect.

arXiv comment24 Pages, 11 figures, accepted for publication in ApJ

References in corpus (18)

• An Observational Overview of Solar Flares
• Particle Acceleration by a Solar Flare Termination Shock
• The Relationship Between Solar Radio and Hard X-ray Emission
• Imaging Spectroscopy of Solar Radio Burst Fine Structures
• A decade of solar Type III radio bursts observed by the Nancay Radioheliograph 1998-2008
• Tracing Electron Beams in the Sun's Corona with Radio Dynamic Imaging Spectroscopy
• The structure of solar radio noise storms
• Combining visibilities from the Giant Meterwave Radio Telescope and the Nancay Radio Heliograph: High dynamic range snapshot images of the solar corona at 327 MHz
• Location of Narrowband Spikes in Solar Flares
• Conditions for electron-cyclotron maser emission in the solar corona
• Small Scale Microwave Bursts in Long-duration Solar Flares
• Radio Diagnostics of Electron Acceleration Sites During the Eruption of a Flux Rope in the Solar Corona
• A new approach to the maser emission in the solar corona
• Coronal magnetic field and the plasma beta determined from radio and multiple satellite observations
• Fast magnetoacoustic waves in a fan structure above the coronal magnetic null point
• A Scenario for the Fine Structures of Solar Type IIIb Radio Bursts Based on the Electron Cyclotron Maser Emission
• Giant Meterwave Radio Telescope observations of an M2.8 flare: insights into the initiation of a flare-coronal mass ejection event
• Electron acceleration in a post-flare decimetric continuum source

Cited by in corpus (3)

• Densities Probed by Coronal Type III Radio Burst Imaging
• Parametric simulation studies on the wave propagation of solar radio emission: the source size, duration, and position
• Preparing for Solar and Heliospheric Science with the SKAO: An Indian Perspective