Abstract

Broadband radio emission originates from a wide range of astronomical sources, such as the hot plasma of the middle solar corona and the exotic environments found around objects such as radio pulsars. For many of these sources, radio emission mechanisms and regions are not well understood, as they are complex and obscured from direct observation by the ionized media that the emission must traverse as it radiates outward toward the observer. Broadband radio waves from galactic astrophysical sources are delayed and distorted on their paths toward the Earth as they pass through the free electrons that compose a variety of media, some of which include the interstellar medium (ISM), the solar atmosphere, and the ionosphere of our planet. These effects can be significant, from obscuring features of the emission mechanisms to rendering the objects almost undetectable. Radio emissions from astrophysical objects can be employed to both study the sources themselves and probe the media through which the emission travels on its path toward the Earth. In this thesis work, approaches from across modern radio astronomy were employed to study the ionosphere, the middle solar corona, the ISM, and emissions from radio pulsars. A low-frequency radio telescope array was commissioned in the path of totality of the 2024 total solar eclipse to probe the region of emission at 42 MHz in the middle solar corona and observe the ionospheric response to the eclipse. A CLEAN deconvolution algorithm, written in Python, was developed, parameterized, and implemented to both rebuild intrinsic pulses of radio pulsars and probe the composition of the ISM along their line of sight toward the Earth. Finally, a tree dedispersion algorithm, implemented on field programmable gate arrays (FPGAs), was developed and tested to account for the dispersive effects of the ISM on radio transients such as pulsars and fast radio bursts.

Library of Congress Subject Headings

Solar radio emission; Radio astronomy; Ionosphere; Interstellar matter; Pulsars; Sun--Corona

Publication Date

8-2025

Document Type

Dissertation

Student Type

Graduate

Degree Name

Astrophysical Sciences and Technology (Ph.D.)

Department, Program, or Center

Physics and Astronomy, School of

College

College of Science

Advisor

Michael Lam

Advisor/Committee Member

Scott Ransom

Advisor/Committee Member

Michael Zemcov

Campus

RIT – Main Campus

Plan Codes

ASTP-PHD

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