Radio-changing State Quasars in the VLA Sky Survey

Energetic feedback by the large-scale lobes of radio galaxies with extents of hundreds of kiloparsecs is a key driver of the co-evolution of galaxies and supermassive black holes. However, the role and impact of feedback by compact (< 1 kpc), sub-galactic jets interacting with the interstellar medium, particularly at “cosmic noon” (z = 1-3), remains an open question. A promising strategy for identifying compact jets is through multi-epoch radio surveys. We present an on-going study of optical and infrared quasars that were recently discovered to be radio-loud in the Very Large Array Sky Survey (VLASS), but were classified as radio-quiet just 1-2 decades ago in previous radio surveys. The “radio-changing state” quasars in our sample likely harbor jets that are compact due to youth and/or re-orientation. The emergence of newly radio-loud quasars on human timescales challenges the perception of radio-loudness as a fixed property of the quasar population. We discuss implications for our understanding of radio jet lifecycles and the potential importance of feedback from compact jets.