Physics & Astronomy ETDs

Publication Date



Though active galaxies have been studied since the inception of radio astronomy, there remain several large gaps in our understanding. Chief among these, is how the jets possessed by the radio loud variety are ignited. A sub-population of radio galaxies known as compact symmetric objects (CSOs) seem to possess newly formed radio jets (100s to 1000s years old). Selecting these sources from the VLBA Imaging and Polarimetry Survey (VIPS), a survey of over 1000 compact radio sources, yields the opportunity to establish an understanding of these sources and what might have caused their recent radio activity. Starting with the VIPS survey we identified 120 CSO candidates, and then performed multi-frequency followup observations to either confirm or deny them as CSOs. We have confirmed 24 CSOs within VIPS and 33 candidates remain. Two of the newly identified CSOs exhibit linearly polarized emission, a rare property within the class. The statistics of the VIPS CSO sample are also investigated to shed light on these nascent radio galaxies. Detailed analysis was performed on two particular sources, the newly classified CSO J11584+2450 and complicated core-jet J16021+3326, in identifying these atypical sources. The observations of CSOs are interpreted within the AGN unification paradigm. The observations of HI absorption toward their cores and polarization of CSOs both tentatively support unification.

Degree Name


Level of Degree


Department Name

Physics & Astronomy

First Committee Member (Chair)

Pihlstrom, Ylva

Second Committee Member

Walker, R. Craig

Third Committee Member

Henning, Patricia

Project Sponsors

National Radio Astronomy Observatory




Radio galaxies, Galaxies--Evolution, Radio sources (Astronomy), Astrophysical jets.

Document Type