Language
English (en)
Date of Award
Spring 5-12-2025
Degree Name
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Restricted/Unrestricted
Unrestricted
Abstract
Active galactic nuclei (AGN) are supermassive black holes that reside at galactic centers and are actively accreting matter. In approximately 10% of cases, AGN produce relativistic jets: collimated streams of particles that travel for thousands of light years and have been detected at TeV energies by ground-based gamma-ray observatories. However, the mechanisms that accelerate particles beyond the TeV scale are largely unknown. Currently, only 56 objects are confirmed to accelerate particles to these extreme energies. Here we provide a selection of over 150 sources that exhibit infrared (IR) and X-ray emission profiles similar to those of the 56 TeV sources. In performing this selection, we develop new constraints on the IR and X-ray emissions of TeV-emitting sources using data from the WISE ALLSKY (WISEA) catalog and the eROSITA-DE Data Release 1. We compare our candidates to existing catalogs interested in selecting TeV-emitting AGN and find a selection of 35 previously unidentified candidate sources for extreme particle emission. Within this selection 32 of these sources are not detected by Fermi-LAT as gamma-ray sources, despite exhibiting IR and X-ray emission profiles characteristic of TeV sources. With further study, these 32 sources will motivate a correlation between the X-ray and TeV emissions of AGN. TeV observations of the candidates proposed in our work will unveil new constraints on the emissions of relativistic jets. With improved constraints, better theoretical models of particle acceleration within relativistic jets can be developed and our understanding of galactic/black hole evolution and structure formation in the universe can be refined.
Mentor
Manel Errando
Additional Advisors
Andrea Gokus
Recommended Citation
Metzger, Cassidy M.; Errando, Manel; and Gokus, Andrea, "In Search of Extreme Extragalactic Energy: A catalog of TeV-emitting BL Lac candidates from eROSITA and WISE" (2025). Senior Honors Papers / Undergraduate Theses. 66.
https://openscholarship.wustl.edu/undergrad_etd/66
A complete list of the candidate sources and their associated TeVCat, Fermi-LAT, Radio, BZCAT, and 3HSP counterparts.
Comments
A paper that is a more evolved version of this work is currently in preparation to be submitted to The Astrophysical Journal by 2025.