Decameter Stationary Type IV Burst in Imaging Observations on the 6th of September 2014

TL;DR

This paper presents the first radio imaging observations of a decameter stationary Type IV solar burst on September 6, 2014, revealing its evolution and association with solar flares and a coronal mass ejection.

Contribution

It provides the first detailed imaging and analysis of a decameter stationary Type IV burst using the UTR-2 heliograph and multi-instrument data, linking it to solar flares and CMEs.

Findings

The burst was confined within a high coronal loop.

The radio emission had a double-humped profile linked to flare activity.

The source showed dynamic evolution over 3 hours.

Abstract

First-of-its-kind radio imaging of decameter solar stationary type IV radio burst has been presented in this paper. On 6 September 2014 the observations of type IV burst radio emission have been carried out with the two-dimensional heliograph based on the Ukrainian T-shaped radio telescope (UTR-2) together with other telescope arrays. Starting at 09:55 UT and throughout 3 hours, the radio emission was kept within the observational session of UTR-2. The interesting observation covered the full evolution of this burst, "from birth to death". During the event lifetime, two C-class solar X-ray flares with peak times 11:29 UT and 12:24 UT took place. The time profile of this burst in radio has a double-humped shape that can be explained by injection of energetic electrons, accelerated by the two flares, into the burst source. According to the heliographic observations we suggest the burst source was confined within a high coronal loop, which was a part of a relatively slow coronal mass ejection. The latter has been developed for several hours before the onset of the event. Through analyzing about 1.5 million of heliograms (3700 temporal frames with 4096 images in each frame that correspond to the number of frequency channels) the radio burst source imaging shows a fascinating dynamical evolution. Both space-based (GOES, SDO, SOHO, STEREO) data and various ground-based instrumentation (ORFEES, NDA, RSTO, NRH) records have been used for this study.