Moving solar radio bursts and their association with coronal mass ejections

Abstract

Context: Solar eruptions, such as coronal mass ejections (CMEs), are often accompanied by accelerated electrons that can in turn emit radiation at radio wavelengths. This radiation is observed as solar radio bursts. The main types of bursts associated with CMEs are type II and type IV bursts that can sometimes show movement in the direction of the CME expansion, either radially or laterally. However, the propagation of radio bursts with respect to CMEs has only been studied for individual events. Aims: Here, we perform a statistical study of 64 moving bursts with the aim to determine how often CMEs are accompanied by moving radio bursts. This is done in order to ascertain the usefulness of using radio images in estimating the early CME expansion. Methods: Using radio imaging from the Naçay Radioheliograph (NRH), we constructed a list of moving radio bursts, defined as bursts that move across the plane of sky at a single frequency. We define their association with CMEs and the properties of associated CMEs using white-light coronagraph observations. We also determine their connection to classical type II and type IV radio burst categorisation. Results: We find that just over a quarter of type II and half of type IV bursts that occurred during the NRH observing windows in Solar Cycle 24 are accompanied by moving radio emission. All but one of the moving radio bursts are associated with white--light CMEs and the majority of moving bursts (90%) are associated with wide CMEs (>60 degrees in width). In particular, all but one of the moving bursts corresponding to type IIs are associated with wide CMEs; however, and unexpectedly, the majority of type II moving bursts are associated with slow white-light CMEs (<500 km/s). On the other hand, the majority of moving type IV bursts are associated with fast CMEs (>500 km/s).

5 pages, 2 figures, 1 table

References in corpus (7)

• Variable emission mechanism of a Type IV radio burst
• Three-dimensional reconstruction of CME-driven shock-streamer interaction from radio and EUV observations: a different take on the diagnostics of coronal magnetic fields
• Importance of CME Radial Expansion on the Ability of Slow CMEs to Drive Shocks
• Width of Radio-Loud and Radio-Quiet CMEs
• Synchrotron Radio Emission from a Fast Halo Coronal Mass Ejection
• On the occurrence of type IV solar radio bursts in the solar cycle 24 and their association with coronal mass ejections
• Electron acceleration and radio emission following the early interaction of two coronal mass ejections

Cited by in corpus (13)

• Stellar Coronal Mass Ejections
• Type II radio bursts and their association with coronal mass ejections in solar cycles 23 and 24
• A type II solar radio burst without a coronal mass ejection
• Shock-accelerated electrons during the fast expansion of a coronal mass ejection
• Coronal mass ejections and type II radio emission variability during a magnetic cycle on the solar-type star $\epsilon$ Eridani
• Trends and Characteristics of High-Frequency Type II Bursts Detected by CALLISTO Spectrometers
• Searching for stellar flares from low mass stars using ASKAP and TESS
• Inter-planetary type-IV solar radio bursts: A comprehensive catalog and statistical results
• Assessing the spectral characteristics of band splitting type II radio bursts observed by CALLISTO spectrometers
• Type IV Radio Bursts and Associated Active Regions in the Sunspot Cycle 24
• Interferometric imaging, and beam-formed study of a moving Type IV Radio burst with LOFAR
• Estimating the lateral speed of a fast shock driven by a coronal mass ejection at the location of solar radio emissions
• Modelling gyrosynchrotron emission from coronal energetic electrons in a CME flux rope