TY - UNPB
T1 - Emergence of a radio jet in the changing-look AGN 1ES 1927+654
AU - Meyer, Eileen T.
AU - Laha, Sibasish
AU - Shuvo, Onic I.
AU - Roychowdhury, Agniva
AU - Green, David A.
AU - Rhodes, Lauren
AU - Hankla, Amelia M.
AU - Philippov, Alexander
AU - Mbarek, Rostom
AU - laor, Ari
AU - Begelman, Mitchell C.
AU - Sadaula, Dev R.
AU - Ghosh, Ritesh
AU - Bruni, Gabriele
AU - Panessa, Francesca
AU - Guainazzi, Matteo
AU - Behar, Ehud
AU - Masterson, Megan
AU - Zhang, Haocheng
AU - Yang, Xiaolong
AU - Gurwell, Mark A.
AU - Keating, Garrett K.
AU - Williams-Baldwin, David
AU - Bray, Justin D.
AU - Bempong-Manful, Emmanuel K.
AU - Wrigley, Nicholas
AU - Bianchi, Stefano
AU - Ricci, Federica
AU - La Franca, Fabio
AU - Kara, Erin
AU - Georganopoulos, Markos
AU - Oates, Samantha
AU - Nicholl, Matt
AU - Pal, Main
AU - Cenko, S. Bradley
PY - 2024/6
Y1 - 2024/6
N2 - We present multi-frequency (5-345 GHz) and multi-resolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic nuclei (CL-AGN). The source was first designated a CL-AGN after an optical outburst in late 2017 and has since displayed considerable changes in X-ray emission, including the destruction and rebuilding of the X-ray corona in 2019-2020. Radio observations prior to 2023 show a faint and compact radio source not unusual for radio-quiet AGN. Starting in February 2023, 1ES 1927+654 began exhibiting a radio flare with a steep exponential rise, reaching a peak 60 times previous flux levels, and has maintained this higher level of radio emission for nearly a year. The 5-23 GHz spectrum is broadly similar to gigahertz-peaked radio sources, which are understood to be young radio jets less than ~1000 years old. Recent high-resolution VLBA observations at 23.5 GHz now show resolved extensions on either side of the core, with a separation of 0.14 pc, consistent with a new and mildly relativistic bipolar outflow. A steady increase in the soft X-ray band (0.3-2 keV) concurrent with the radio may be consistent with jet-driven shocked gas, though further observations are needed to test alternate scenarios. This source joins a growing number of CL-AGN and tidal disruption events which show late-time radio activity, years after the initial outburst....
AB - We present multi-frequency (5-345 GHz) and multi-resolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic nuclei (CL-AGN). The source was first designated a CL-AGN after an optical outburst in late 2017 and has since displayed considerable changes in X-ray emission, including the destruction and rebuilding of the X-ray corona in 2019-2020. Radio observations prior to 2023 show a faint and compact radio source not unusual for radio-quiet AGN. Starting in February 2023, 1ES 1927+654 began exhibiting a radio flare with a steep exponential rise, reaching a peak 60 times previous flux levels, and has maintained this higher level of radio emission for nearly a year. The 5-23 GHz spectrum is broadly similar to gigahertz-peaked radio sources, which are understood to be young radio jets less than ~1000 years old. Recent high-resolution VLBA observations at 23.5 GHz now show resolved extensions on either side of the core, with a separation of 0.14 pc, consistent with a new and mildly relativistic bipolar outflow. A steady increase in the soft X-ray band (0.3-2 keV) concurrent with the radio may be consistent with jet-driven shocked gas, though further observations are needed to test alternate scenarios. This source joins a growing number of CL-AGN and tidal disruption events which show late-time radio activity, years after the initial outburst....
U2 - 10.48550/arXiv.2406.18061
DO - 10.48550/arXiv.2406.18061
M3 - Working paper
SP - 1
EP - 17
BT - Emergence of a radio jet in the changing-look AGN 1ES 1927+654
PB - arXiv
ER -