Proceedings of the International Astronomical Union

Contributed Papers

Damping of non-isothermal hot coronal loops oscillations

M. Luna-Cardozoa1, R. Erdélyia1 and César A. Mendoza-Briceñoa2

a1 SP2RC, Department of Applied Mathematics, University of Sheffield, Sheffield S3 7RH, UK emails: m.luna@sheffield.ac.uk; robertus@sheffield.ac.uk

a2 Centro de Física Fundamental CFF, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela, email: cesar@ula.ve

Abstract

Here we investigate longitudinal waves in non-isothermal hot (T ≥ 5.0 MK) coronal loops. Motivated by SOHO SUMER and Yohkoh SXT observations and taking into account gravitational stratification, thermal conduction, compressive viscosity, radiative cooling, and heating, the governing equations of 1D hydrodynamics is solved numerically for standing wave oscillations along a magnetic field line. A semicircular shape is chosen to represent a coronal loop. It was found that the decay time of standing waves decreases with the increase of the initial temperature and the periods of oscillations are affected by the different initial velocities and loop lengths studied by the numerical experiments. The predicted decay times are within the range of values inferred from Doppler-shift oscillations observed by SUMER in hot coronal loops.

Keywords

  • waves;
  • hydrodynamics;
  • Sun: Corona;
  • Sun: oscillations