Abstract Details

Name: Surajit Mondal
Affiliation: National Centre for Radio Astrophysics
Conference ID: ASI2020_342
Title : Evidence for impulsive heating in quiet sun?
Authors and Co-Authors : Surajit Mondal, Divya Oberoi, Atul Mohan
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : Coronal heating problem is a long standing mystery in solar physics. There are several theories which try to address this issue. Although it is well established that energy stored in the magnetic field due to random convective motions is the energy reservoir details of how this energy is converted into heat energy is not well understood. There are a class of theories according to which heat is dumped into the corona impulsively. The details about how the energy is dumped varies from theory to theory. However, a necessary condition for these theories is that the number of such impulsive events should satisfy Hudson's criterion. Hudson's criterion states that if the number of events with energy E follows a powerlaw, then the powerlaw index should be less than -2. The validity of this condition in active regions has been shown in the past by several people in different wavebands including radio. Doing this experiment in radio band is important as radio is very sensitive even to very small flares due to their higher brightness temperature compared to the background sun. To the best of our knowledge, a similar study has not been done with quiet sun in the radio band. In this work, we have analysed 70 minutes of data when the sun was very quiet at 0.5s cadence at 4 frequency bands. We show in a very robust manner that the powerlaw index is smaller than 2 at all four frequencies at a significance ranging from 3 to 11 sigma. If this result is validated with further observations spanning over different days and different solar activity, this will give a strong constraint on theories of coronal heating.