|Indian Institute of Technology, Varanasi (IIT-BHU)
|Conference ID :
|Role of Heating-Cooling Misbalance on the Properties of Slow Magnetoacoustic Waves
|1)Abhinav Prasad (Department of Physics, Indian Institute of Technology, BHU, Varanasi) 2)Abhishek K. Srivastava (Department of Physics, Indian Institute of Technology, BHU, Varanasi) 3)Tongjiang Wang (The Catholic University of America and NASA Goddard Space flight Centre) 4)Kartika Sangal (Department of Physics, Indian Institute of Technology, BHU, Varanasi)
|Abstract Category :
|Sun and the Solar System
|The radiative cooling and coronal heating processes are important in the evolution of slow-mode oscillations and the specific mechanism of coronal heating is still a widely discussed and studied topic in the solar context. Heating-Cooling Misbalance refers to the misbalance between the radiative losses and an assumed unknown coronal heating function created due to the MHD oscillations perturbing the equilibrium plasma parameters. Recently many theoretical studies have explored a density and temperature dependent coronal heating function and used it to analyze and explain the different properties of MHD waves & oscillations observed in solar coronal loops. We have built on several of these studies to explain the damping and phase properties of standing and propagating slow-mode magnetoacoustic waves in solar coronal loops by deriving a new comprehensive dispersion relation taking into account the effect of thermal conductivity, compressive viscosity, radiative cooling and heating-cooling misbalance. Furthermore, new mathematical expressions for the polytropic index and phase shift between density and temperature perturbations of slow-mode waves have been derived. We have systematically solved the dispersion relation and provided a comprehensive parametric study for a wide range of loop parameters viz., density, temperature, loop length. Comparing our results with the observations we have been able to give a new scaling law for the damping time(s) and period(s) which matches quite closely with the SUMER/SDO observations and the inclusion of heating-cooling misbalance brings the theoretical data points closer to the observations. We have also provided an explanation for the coronal plasma conditions that can better explain the observed phase shifts and polytropic index for the case of standing and propagating slow-mode waves.