Prosiectau Ffiseg ar gyfer myfyrwyr bl.3 a bl.4

Disgrifiad prosiect

Diagnostics of quiet Sun magnetic fields

(supervisor: David Kuridze)

Nature of project: data analysis, data analysis

Available to students on full-time physics degree schemes or joint students.

Project description and methodology

The Solar surface is populated by small-scale magnetic elements, such as magnetic bright points and pores. These structures have a significant contribution in the magnetism and dynamism of the solar atmosphere.

The aim of this project is to measure the vertical (with respect to the surface) magnetic field strength of these features using circularly polarised profiles (Stokes V) in the magnetically sensitive spectral line. The student will use high-resolution spectropolarimetric data from the Swedish 1-m Solar Telescope. The data will be used for calculation of a spatially averaged LoS magnetic field of the small-scale magnetic elements employing the weak-field approximation and/or center of gravity method.

A successful project will develop beyond the above in one/some of the following directions:
The main way to develop this project further is to measure the plane of the sky (horizontal with respect to the surface) component of the magnetic field using linear polarisation profiles (Stokes Q and U).

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: For a 4th year project, the student can measure magnetic field strength as the function of time and investigate how the magnetic elements develop/change in time.

Please speak to David Kuridze (dak21) if you consider doing this project.

Initial literature for students:

  1. The Sun as a guide to Stellar Physcis, Editors: Oddbjørn Engvold, Jean-Claude Vial, Andrew Skumanich (book, chapter 5.3), ELSEVIER, 2019
  2. Kuridze, D., Mathioudakis, M., Morgan, H., et al. 2019, The Astrophysical Journal, 874, 126
  3. Wiegelmann, T., Thalmann, J., Solanki, S., 2014, The Astronomy and Astrophysics Review, Volume 22, 78, 106
  4. Uitenbroek, H., Astrophysical Journal, 592, 1225

Novelty, degree of difficulty and amount of assistance required

Fully processed spectropolarimetric data and assistance how to analyse it will be provided. IDL/Python training will be provided by the supervisor.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Review of mathematical formalism (Stokes formalism) of polarization of lightend of October
Learning how to open/load the SST spectropolarimetric data in IDL/Python and develop the codeChristmas
Applying weak-field approximation and/or center of gravity method to the spectropolariemtric profilesend of February
Determine the magnetic field Easter