Year: 2026
Type: article
Abstract: We present ongoing radio observations of the tidal disruption event (TDE) AT2018hyz, which was first detected in the radio at 972 days after disruption, following multiple nondetections from earlier searches. The new observations presented here span ≈1370–2160 days and 0.88–240 GHz. We find that the light curves continue to rise at all frequencies during this time period, following a power law of about F ν ∝ t 3 (compared to F ν ∝ t 5.7 at 972–1400 days) and reaching a peak luminosity of L ≈ 10 40 erg s −1 , comparable to the luminosity of the relativistic TDE Sw 1644+57 on the same timescale. The multifrequency data indicate that the peak frequency does not significantly evolve over the 1030 days span of our observations, while the peak flux density increases by an order of magnitude. The observed behavior is consistent with two possible scenarios: (i) a delayed spherical outflow launched about 620 days postdisruption with a velocity of ≈0.3 c and an energy of ∼10 50 erg; or (ii) a highly off-axis (≈80°–90°) relativistic jet with a Lorentz factor of Γ ∼ 8 and E K ≈ 10 52 erg. Continued radio observations to capture the light-curve peak, as well as very long baseline interferometry observations, could distinguish between these scenarios.
Source: The Astrophysical Journal
Authors: Yvette Cendes, Edo Berger, Paz Beniamini, Ramandeep Gill, Tatsuya Matsumoto, Kate D. Alexander, Michael F. Bietenholz, Aprajita Hajela, Collin T. Christy, Ryan Chornock, Sebastian Gomez, Mark A. Gurwell, Garrett K. Keating, Tanmoy Laskar, Raffaella Margutti, Ramprasad Rao, Natalie Velez, Mark H. Wieringa
Institutions: University of Oregon, Center for Astrophysics Harvard & Smithsonian, Open University of Israel, George Washington University, Universidad Nacional Autónoma de México, Kyoto University, The University of Tokyo, University of Arizona, York University, University of Copenhagen, University of California, Berkeley, Radboud University Nijmegen, University of Utah, Commonwealth Scientific and Industrial Research Organisation
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, Smithsonian Institution, National Aeronautics and Space Administration, National Radio Astronomy Observatory, Australian Government, Commonwealth Scientific and Industrial Research Organisation, National Research Foundation, Academia Sinica, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Smithsonian Astrophysical Observatory, National Institutes of Natural Sciences, Kavli Institute for Theoretical Physics, University of California, Santa Barbara
OpenAlex ID: W7128075367