Undergraduate Honors Theses

Thesis Defended

Spring 2018

Document Type

Thesis

Type of Thesis

Departmental Honors

Department

Astronomy

First Advisor

Dr. Mark Rast

Second Advisor

Dr. Valentin Martinez-Pillet

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Abstract

Observations of the solar photosphere show many spatially compact Doppler velocity events with short life spans and extreme values. In the IMaX spectropolarimetric inversion data of the first flight of the SUNRISE balloon in 2009 these striking flashes in the intergranule lanes and complementary outstanding values in the centers of granules have line of sight Doppler velocity values in excess of 4σ from the mean. We conclude that values outside 4σ are a result from the superposition of the granulation flows and the p-modes.

To determine how granulation and p-modes contribute to these outstanding Doppler events, I separate the two components using the Fast Fourier Transform. I produce the power spectrum of the spatial wave frequencies and their corresponding frequency in time for each image, and create a k-omega filter to separate the two components. Using the filtered data, test the hypothesis that extreme events occur because of strict superposition between the p-mode Doppler velocities and the granular velocities. I compare event counts from the observational data to those produced by random superposition of the two flow components and find that the observational event counts are consistent with the model event counts in the limit of small number statistics. Poisson count probabilities of event numbers observed are consistent with expected model count probability distributions.

set2.gif (57056 kB)
Animation of the original, granulation, and p-mode field of view..

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