Research project
The objective of my project is to study magnetic reconnection in the solar transition region, a part of the Sun's atmosphere that is between the chromosphere and the corona. I am looking at far-ultraviolet spectra and images that come from the Interface Region Imaging Spectrograph (IRIS) to identify explosive events (EEs) that occur in this region. The data can be found at the IRIS Website.
EEs in the transition region occur at temperatures between 20,000 and 250,000K. They are easy to spot in a spectrum, as they cause broadening of emission lines. This happens because the EEs have a high doppler velocity. EEs are signatures of magnetic reconnection in the Sun, and they occur quite frequently. The first part of my project included looking at the spectra from IRIS and identifying where and when these EEs have occurred. I then classified many of the EEs based on their spectra and morphology. I noted whether the EEs were red-shifted or blue-shifted as well as a number of other features based on their spectra, and then I also categorized the EEs as loops, compact, or footpoints, depending on their physical features. I plotted the spectra of each individual explosive event and determined their median velocities, and analyzed these results statistically.
The next half of my project involved analyzing just one particularly complicated explosive event. I made color images of the EE in which the each spatial and temporal point of the event had a color associated with it based on either its velocity and intensity or its velocity line width and intensity. These images can be found in my logs from weeks 7 and 8. I studied the relationship between the velocity and line width of the points.
One surprising result was that parts of the explosive event were moving at much higher speeds than we expected. By further analyzing this event, we hope to gain insight into the mechanism of magnetic reconnection. The EE appears to contain multiple sub-events, and the timescale and length scale of such sub-events may help us understand what type of instability is causing the reconnection.
Here are some images created with Dr. Kankelborg's software, and here is a cool video. The left side is the spectrum and the right side is the image and the slit. The boxes on the images indicate where we can see line broadenings, and thus explosive events! Look in the weekly logs for more details and to see the graphs and the rest of the graphics I created.
Research log
Week 1: Learning about IRIS and my part of the project.
Week 2: Making videos of the IRIS data.
Week 3: Identifying explosive events.
Week 4: Programming and plotting explosive event spectra.
Week 5: Plotting the spectra and making histograms.
Week 6: Examining individual explosive events.
Week 7: Making color images.
Week 8: Improving color images and examining line widths.
Resources
Here are some quick links:
Look at the REU Homepage that I designed!
The IRIS website.
Check out my pictures from Montana.
One of the videos I made of the IRIS data.
Here is my midterm presentation.
And here is my final presentation!
