The CME source region in LOFAR related simulations: Numerical studies of Coronal Mass Ejections to prepare observations of the LOw Frequency ARay

• Applicant: Professor Dr. Joachim Vogt
• Subject Area: Astrophysics and Astronomy
• Term: from 2005 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 16606065

• Final Report Year: 2011

Final Report Abstract

New generation radio observatories such as the LOw Frequency ARray (LOFAR) allow to observe solar and cosmic phenomena in a largely unexplored frequency range with unprecedented resolution. Radio signatures of solar activity phenomena are produced by the complex interplay of a chain of microphysical processes in dynamical macroscopic settings such as reconnection sites or shock fronts. We modeled the formation of type II radio bursts by means of magnetohydrodynamic (MHD) simulations of the source region of coronal mass ejections (CMEs). A radio emission model was defined in terms of MHD variables to parametrize key plasma kinetic processes, such as shock-drift acceleration and Langmuir wave generation from unstable beam distributions in the upstream region of a shock. The model was combined with the MHD simulation to yield distributions of volume emissivity and, finally, dynamic radio spectra which were then compared with observed time-frequency spectra. Despite the oversimplified modeling approach, the synthetic dynamic spectra exhibit narrow bands that are qualitatively similar to observed type II bursts.

Publications

• (2005). Science cases for a lunar radio observatory. To Moon and Beyond (DGLR Meeting), Bremen, September 2005
  Vogt, J., M. Brüggen, J. Schmidt, G. Haerendel, and S. Malapaka
  
• (2005). Solar eruptions and their radio detection. COPAP Meeting, Bochum, July 2005
  Schmidt, J., J. Vogt, M. Brüggen, and G. Haerendel
  
• (2005). Sonneneruptionen und deren Radiodetektion. DPG Meeting, Berlin, March 2005
  Schmidt, J., J. Vogt, M. Brüggen, Peter Cargill, and G. Haerendel
  
• A German Contribution to LOFAR. Annual Meeting of the Astronomische Gesellschaft, Köln, June 2006
  Brüggen, M.
  
• From the Cosmos to the Sun: The quest for a radio emission model. Potsdam workshop ’Solar Physics and Space Weather with LOFAR’, October 2006
  Hoeft, M., J. Vogt, and M. Brüggen
  
• Cosmic Shock Fronts - As seen with a Radio Telescope Colloquium. TU Berlin, December 2007
  Hoeft, M., J. Vogt, and M. Brüggen
  
• Radio emission of structure formation shocks. Workshop, Mizpe-Ramon, Israel June 2007
  Hoeft, M., Vogt, J., and Brüggen, M.
  
• The radio signature of structure formation shocks. Colloquium, Kiepenheuer Institute for Solar Physics, Freiburg, March 2007
  Hoeft, M., Vogt, J., and Brüggen, M.
  
• Cosmic Magnetism. Conference on Magnetic Fields in the Universe II, Cozumel, January 2008
  Brüggen, M.