Michael Knoelker

Publications (2)0 Total impact

• Source

  Available from: Wolfgang Schmidt

  Article: Magnetic loops in the quiet Sun

  Thomas Wiegelmann, Sami K. Solanki, Juan Borrero, Valentin Martinez Pillet, J. C. del Toro Iniesta, Vicente Domingo, J. A. Bonet Navarro, Peter Barthol, Achim Gandorfer, Michael Knoelker, Wolfgang Schmidt, Alan M. Title
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  ABSTRACT: We investigate the fine structure of magnetic fields in the atmosphere of the quiet Sun. We use photospheric magnetic field measurements from {\sc Sunrise}/IMaX with unprecedented spatial resolution to extrapolate the photospheric magnetic field into higher layers of the solar atmosphere with the help of potential and force-free extrapolation techniques. We find that most magnetic loops which reach into the chromosphere or higher have one foot point in relatively strong magnetic field regions in the photosphere. $91%$ of the magnetic energy in the mid chromosphere (at a height of 1 Mm) is in field lines, whose stronger foot point has a strength of more than 300 G, i.e. above the equipartition field strength with convection. The loops reaching into the chromosphere and corona are also found to be asymmetric in the sense that the weaker foot point has a strength $B < 300$ G and is located in the internetwork. Such loops are expected to be strongly dynamic and have short lifetimes, as dictated by the properties of the internetwork fields. Comment: accepted for ApJL Sunrise special issue, 8 Pages, 4 Figures
  09/2010;
• Source

  Available from: Dirk Soltau

  Article: Flight control software for the wave-front sensor of SUNRISE 1m balloon telescope

  Alexander Bell, Peter Barthol, Thomas Berkefeld, Bernhard Feger, Achim M. Gandorfer, Frank Heidecke, Michael Knoelker, Valentin M. Pillet, Wolfgang Schmidt, Michael Sigwarth, Sami K. Solanki, Dirk Soltau, Alan M. Title
  SPIE, v.7740 (2010).