Abstract


  KINK AND SAUSAGE OSCILLATIONS OF A QS MINI LOOP

  N. Dadashi, University of Zanjan, dadashi@znu.ac.ir
  H. Safari, University of Zanjan, Iran, safari@znu.ac.ir
  M. Gholami, University of Zanjan, Iran,
  M. Abedini, Islamic Azad University of Savadkouh, Iran, mohsen_abedini@yahoo.com

Looking closely to QS structures at EUV wavelengths, one can see many tiny bright spots having one or more loop like oscillating structures. We present observational evidence of detecting MHD kink (m=1) and Sausage (m=0) modes in a QS mini loop using 171 images of AIA/SDO with 0.6 arc second spatial and 12 sec temporal resolutions. The studied loop is located in a QS region close to the disk center to avoid projection effects. Several cross sections along the loop are selected to make time-distance maps. A Gaussian function is fitted to each time-step cross section of the selected parts of the loop to find the center of brightness. Afterward, a sine function is fitted to time distance maps to extract the amplitude, period, initial phase, and damping rate of the loop oscillation. For Sausage modes the width of the fitted Gaussian profiles are considered as the widths of the loop. The studied loop shows MHD kink and sausage modes with 4.5-11 and 12-15 minutes periods, respectively. The amplitudes of the kink oscillations are 1.2 Mm at apex and 0.9 Mm and 0.6 m at the two footpoints of the loop which is expectable for the Kink modes.