Solar Intern Program Project:
 
 Title: Characterizing Thermal Plasma During Solar Eruptions

Type of Project: Data Analysis

Skills/Interest Required: Students that are interested in solar physics. Python/IDL or other programming skills a plus.

Mentor: Dr. Kathy Reeves, Dr. Mark Weber

Email: kreeves_at_cfa.harvard.edu

Background:

It has been widely accepted that solar eruptions are powered by the catastrophic release of magnetic energy via reordering of the Suns magnetic fields. The energy released during solar eruptions is transported and converted in the flaring region in the forms of electromagnetic radiation, high-speed bulk flows, heated plasma, and accelerated particles. Some outflows are observed as dark voids flowing through a bright plasma sheet that forms above the flare loops, referred to as supra-arcade downflows (SADs). Several models exist to explain SADS, but they have varying predictions for the temperature structure of SADs. Thus this project aims to quantify aims to characterize the thermal state of the supra-arcade downflows to gain statistical insight into their properties.

Project:

We will largely use data from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory. This instrument takes imaging data of the entire Sun in several EUV bandpasses every twelve seconds. Six of the AIA EUV bandpasses are dominated by emission from Fe lines (94, 131, 171, 193, 211, 335 A). We will also include X-ray images from Hinode/XRT in this analysis where available. We will use this data to perform differential emission measure calculations, which give a distribution of the plasma as a function of temperature. There are currently data for many flares that have SADs associated with them, providing a good basis for a statistical sample.

Figure 1: An image of an eruption in the AIA 131 A channel, showing supra-arcade downflows (in white box). From Reeves et al., ApJ, 2017.

   
 

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