Abstract


  MULTI-WAVELENGTH ANALYSIS OF QUASI-PERIODIC PULSATIONS IN X-RAYS DURING A SOLAR FLARE

  P. Chowdhury, Kyung Hee University / Calcutta University , parthares@gmail.com
  A. Srivastava, Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005, India, asrivastava.app@iitbhu.ac.in
  L. Dolla, Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels, Belgium, laurent.dolla@oma.be
  M. Dominique, Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels, Belgium, marie.dominique@oma.be
  Y. Moon , School of Space Research, Kyung Hee University, Yongin, Gyeonggi-Do, 446-701, Korea, moonyj@khu.ac.kr

B. N. Dwivedi, Department of Physics, Indian Institute of Technology (Banaras Hindu University), India, bnd.app@itbhu.ac.in

Quasi-periodic oscillations in soft X rays (SXR) during solar flares are not fully understood due to instrument limitations, especially the absence of imaging observations of SXR oscillations. We explore the quasi-periodic oscillations in SXR at 3 25 keV in the decay phase of an M 8.9 class solar flare observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) on 4 June 2007. Time spectra of the signals integrated over the emission source are investigated with the use of power spectral decomposition techniques. It reveals the presence of some statistically significant QPPs commonly existing in more than one energy band of soft X rays (e.g., 26 s; 70 s; and 180 s). We explain the nature of the detected QPPs in terms of various possible MHD modes evolved simultaneously in the flaring loop.