Physics projects for Y3 and Y4 students

Project description

Mapping the velocity of flare coronal loops

(supervisor: David Kuridze)

Nature of project: data analysis, experimental

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

Project description and methodology

Solar flares are rapid energy releases within active regions caused by the reconnection of the coronal magnetic field resulting in coronal plasma heating to temperatures beyond tens of millions of kelvins. On September 10 2017 Active Region (AR) 12673 produced one of the most powerful flare (X8.2-class) of solar cycle 24. The flare led to intense heating and evaporation of dense chromospheric plasma into the loop system. The chromospheric plasma underwent rapid cooling (condensation) and the coronal loops subsequently filled with cool plasma. A well-developed set of flaring coronal loops was observed 10 minutes after the flare peak showing strong downflows of condensed plasma from the loop apex toward the footpoints.

The aim of this project is to measure the line-of-sight (LOS) component of the downflowing plasma motions and produced 2D LOS velocity map (Dopplergram) of the flare loop arcade. The student will use high-resolution spectropolarimetric data from the Swedish 1-m Solar Telescope. The spectral line profiles will be used for calculation of a Doppler shifts to determine the plasma LOS velocity.

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 (POS) component of the velocity and reconstruct 3D velocity map of the flare loop arcade.

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, student can measure LOS velocity as the function of time and investigate how the loop system develops/changes in time

Please speak to David Kuridze 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, ApJ, The Astrophysical Journal, 874, 126
  3. Fletcher, L., Dennis, B. R., Hudson, H. S., et al. 2011, Space Science Reviews, 159, Issue 1-4, 19-106

Novelty, degree of difficulty and amount of assistance required

Student should be able to use IDL. Fully processed spectroscopic data and assistance how to analyse it and measure velocities will be provided.

Project milestones and deliverables (including timescale)

milestoneto be completed by
The basics of spectroscopy (overview)end of October
Learning how to open/load the SST spectroscopic data in IDL and an overview of the basics of the solar flaresChristmas
Fitting the spectra using Gaussian functionend of February
Determine plasma LOS velocities. Easter