Searching for Persistent Radio Sources

Citation

Seebeck, Jerome John (2022) Searching for Persistent Radio Sources. Senior thesis (Major), California Institute of Technology. doi:10.7907/4aj5-gv39. https://resolver.caltech.edu/CaltechTHESIS:06032022-212228226

Abstract

We present a sample of 27 sources from the Very Large Array Sky Survey (VLASS) associated with dwarf galaxies as possible persistent radio sources (PRS). This thesis presents a novel approach of high offset associations between radio sources and optical counterparts from the Galaxy List for the Advanced Detector Era+ (GLADE+) through the use of the Bayesian association algorithm Probabilistic Association of Transients to their Hosts (PATH). We follow up on this sample with SED fitting through UV, optical, and IR photometry to garner accurate star formation and stellar masses for the sample. We use this data to search for high luminosity (excess L_ν ≥ 10²⁹ ergs⁻¹ Hz-1), high offset (> 2"), and high association probability (P(O|x) ≥ 0.93) sources for follow up. Our goal for further follow up is to eliminate possible astrophysical foreground such as AGN, SNe, and star formation as explanation for these sources. We follow up with Keck Low Resolution Imaging Spectrometer (LRIS) optical spectra of 2 sources and find no evidence of AGN activity. We also discuss our VLBA proposal for 11 of our sources to search for compactness of source radio emission, a feature of PRS. Additional follow-up spectroscopy and radio observations are necessary to confirm any of these candidates and PRS due to the large number of foregrounds and this thesis presents a possible list of 27 candidates within VLASS in order to do so.

Thesis Files