Abstract


  ON ESTIMATING THE RADIAL PROFILE OF MAGNETIC FIELD IN CORONAL STREAMERS

  T. Singh, IIT(BHU), Varanasi, talwinder.singh.app11@iitbhu.ac.in
  A. Srivastava, IIT(BHU), Varanasi, India, asrivastava.app@iitbhu.ac.in
  L. Ofman, NASA-GSFC, USA, Leon.Ofman@nasa.gov
  B. Dwivedi, IIT(BHU), Varanasi, India, bnd.app@iitbhu.ac.in

MHD seismology can be utilized to find local coronal conditions from remote observations of wave and plasma parameters. We use STEREO Cor-1 data to observe the kink oscillations in a streamer at various heights caused by a near periodic driver evolved due to two Extreme Ultraviolet(EUV) waves impacting on the streamer consecutively on 7 March 2012. We estimate the phase velocity of the wave by time-delay technique. We also estimate the electron densities inside and outside the steamer using spherically symmetric inversion of polarized brightness images. Assuming the MHD theory of kink waves, estimated properties of the wave and plasma, we estimate the radial profile of magnetic field in the streamer. This matches with the general power-law of decaying coronal magnetic field that is most likely a multipolar field. We provide a new scaling for this decaying radial profile, and compare with the earlier reported profiles of the coronal magnetic fields.