Abstract Details

Name: Bhuwan Joshi
Affiliation: Udaipur Solar Observatory, Physical Research Laboratory
Conference ID: ASI2021_580
Title : A low intensity, long-duration solar eruptive flare and associated type-I solar radio storm: SDO and PRL-CALLISTO observations
Authors and Co-Authors : Bhuwan Joshi (Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313001, India), Prabir K. Mitra (Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313001, India), R. Bhattacharyya (Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313001, India), Kushagra Upadhyay (Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313001, India), Divya Oberoi (National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411007, India), and Christian Monstein (Istituto Ricerche Solari Locarno (IRSOL), Via Patocchi 57, 6605 Locarno Monti, Switzerland)
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : We explore the magnetic configuration and energy release process of a C-class long duration event (LDE). The investigation utilizes data from AIA and HMI on board SDO and PRL-CALLISTO solar radio spectrograph installed at the Udaipur Solar Observatory. This low SXR intensity event is characterized by typical features of LDE flare, viz. extended flare arcade and two-ribbon structures along with a quite prolonged period of soft X-ray emission of ≈3.5 hours. The event displayed two distinct phases of energy release, manifested in terms of both temporal and spatial scales. The GOES soft X-ray time profiles clearly show gradual variations during both the phases that peak at an interval of ≈20 min. The EUV images reveal that the site of energy release progressively changed within the coronal sigmoid during the course of the flare evolution. From multi-channel SDO images, we find that coronal region of the first reconnection event corresponds to a stronger photospheric field showing compact sunspot groups while the second event is associated with weaker and dispersed magnetic field region in the photosphere with no visible signatures of any sunspot. The low frequency radio observations obtained from PRL-CALLISTO system indicates radio emissions to be associated with the second phase of the event only, in the form of type I radio storm in the frequency range of ≈50–180 MHz that sustained for ≈7 min. The synthesis of multi-wavelength observations along with magnetic field extrapolation reveals that flare accelerated electrons trapped near the apex of large-scale coronal loops rooted at the location of flare ribbons of the second phase, caused plasma emission as a type I radio storm.