High speed magnetized flows in the quiet sun

Abstract

This thesis is focused in the study of the quiet Sun photosphere. In particular, in the high speed magnetized flows that can be observed in the solar surface. These events are distinguishable through the detection of highly distorted Stokes V profiles that trace the presence of magnetic plasma which is moving with very high velocities. We have studied these particular types of events using two instruments: IMaX, a vector polarimeter on board the Sunrise balloon mission, and a Spectropolarimeter (SP) on board the Hinode satellite mission. Using the first instrument, we have discovered that these high speed magnetized plasma are related to the emergence of nearly horizontal field in the quiet Sun surface. In fact, most of the detected events are preceded by the emergence of a horizontal magnetic field that can be associated with the top part of a magnetic loop. Using the latter instrument, we focused in the physical properties of these events, performing Stokes inversions to infer the configuration of the physical parameters in the atmosphere. From the data sets measured by Hinode/SP we were able to detect two different types of events. The first ones are loop-like structures that present vertical fields in the footpoints connected by a horizontal magnetic field. Each footpoint displays opposite velocities and inclinations, indicating that the plasma travels from one footpoint to the other with very high velocities. One of these footpoints, the blue-shifted one, always appears at the edge of a granule while the other, the red-shifted one, is always located in an intergranular lane. The magnetic field intensity, at log tau 500 = 0, in both footpoints reaches values of nearly 600 G while the LOS velocity presents values of 5 km/s. The second detected type of events are described as a thin structure composed by vertical fields anchored in intergranular lanes. These structures present distorted Stokes V profiles that are always highly red-shifted. The inversion of the Stokes profiles revealed magnetic field intensities in the order of kG and almost vertical orientations. The process takes place inside a hot atmosphere that produces that the event can be seen as a bright point in a continuum map. The evolution of these events revealed that the complex Stokes V shapes can be reproduced by a local magnetic perturbation that travels from the top of the photosphere (probably from the low chromosphere) to the bottom of the photosphere. Finally, we propose in this thesis the possible mechanisms that could produce these different and complex types of high speed magnetized flows that are present in the quiet Sun photosphere