Seminar: Dr. Kristina Nyland | U.S Naval Research Laboratory (NRL)
In-Person PHYS 401
Location
Physics : 401
Date & Time
April 23, 2025, 11:00 am – 12:00 pm
Description
TITLE: "The Dynamic Lives of Radio Jets in Active Galactic Nuclei”
ABSTRACT: Radio jets and lobes launched by active galactic nuclei (AGN) are thought to play a key role in shaping the evolution of galaxies. To understand how these jets are triggered, grow, and interact with their environments, it is essential to identify them in the early stages of their evolution, when they are still compact and confined within their host galaxies. Despite their significance, young AGN jets have historically been difficult to identify unambiguously due to observational limitations. In this talk, I will present new strategies for identifying young and compact AGN jets using modern radio telescopes, instruments, and surveys that combine multi-epoch, broadband observations with wide-area sky coverage. I will highlight recent findings from my research, including: (1) constraints on jet lifetimes from the VLA Sky Survey suggesting that short-lived jet activity is common; (2) evidence for merger-driven jet triggering based on new Hubble Space Telescope imaging; and (3) early results from low-frequency radio studies with LOFAR and the GMRT constraining the AGN duty cycle. These results provide new insights into AGN jet evolution and their potential influence on galaxy growth. Finally, I will outline ongoing efforts focused on improved identification techniques, opportunities for long-term monitoring, and exploring jet-driven feedback.
ABSTRACT: Radio jets and lobes launched by active galactic nuclei (AGN) are thought to play a key role in shaping the evolution of galaxies. To understand how these jets are triggered, grow, and interact with their environments, it is essential to identify them in the early stages of their evolution, when they are still compact and confined within their host galaxies. Despite their significance, young AGN jets have historically been difficult to identify unambiguously due to observational limitations. In this talk, I will present new strategies for identifying young and compact AGN jets using modern radio telescopes, instruments, and surveys that combine multi-epoch, broadband observations with wide-area sky coverage. I will highlight recent findings from my research, including: (1) constraints on jet lifetimes from the VLA Sky Survey suggesting that short-lived jet activity is common; (2) evidence for merger-driven jet triggering based on new Hubble Space Telescope imaging; and (3) early results from low-frequency radio studies with LOFAR and the GMRT constraining the AGN duty cycle. These results provide new insights into AGN jet evolution and their potential influence on galaxy growth. Finally, I will outline ongoing efforts focused on improved identification techniques, opportunities for long-term monitoring, and exploring jet-driven feedback.
