_version_ 1866915429844254720
author Sfaradi, Itai
Margutti, Raffaella
Chornock, Ryan
Alexander, Kate D.
Metzger, Brian D.
Beniamini, Paz
Duran, Rodolfo Barniol
Yao, Yuhan
Horesh, Assaf
Farah, Wael
Berger, Edo
J., Nayana A.
Cendes, Yvette
Eftekhari, Tarraneh
Fender, Rob
Franz, Noah
Green, Dave A.
Hammerstein, Erica
Lu, Wenbin
Wiston, Eli
Bernstein, Yirmi
Bright, Joe
Christy, Collin T.
Cruz, Luigi F.
DeBoer, David R
Golay, Walter W.
Goodwin, Adelle J.
Gurwell, Mark
Keating, Garrett K.
Laskar, Tanmoy
Miller-Jones, James C. A.
Pollak, Alexander W.
Rao, Ramprasad
Siemion, Andrew
Sheikh, Sofia Z.
Shoval, Nadav
van Velzen, Sjoert
author_facet Sfaradi, Itai
Margutti, Raffaella
Chornock, Ryan
Alexander, Kate D.
Metzger, Brian D.
Beniamini, Paz
Duran, Rodolfo Barniol
Yao, Yuhan
Horesh, Assaf
Farah, Wael
Berger, Edo
J., Nayana A.
Cendes, Yvette
Eftekhari, Tarraneh
Fender, Rob
Franz, Noah
Green, Dave A.
Hammerstein, Erica
Lu, Wenbin
Wiston, Eli
Bernstein, Yirmi
Bright, Joe
Christy, Collin T.
Cruz, Luigi F.
DeBoer, David R
Golay, Walter W.
Goodwin, Adelle J.
Gurwell, Mark
Keating, Garrett K.
Laskar, Tanmoy
Miller-Jones, James C. A.
Pollak, Alexander W.
Rao, Ramprasad
Siemion, Andrew
Sheikh, Sofia Z.
Shoval, Nadav
van Velzen, Sjoert
contents We present the first multi-epoch broadband radio and millimeter monitoring of an off-nuclear TDE using the VLA, ALMA, ATA, AMI-LA, and the SMA. The off-nuclear TDE 2024tvd exhibits double-peaked radio light curves and the fastest evolving radio emission observed from a TDE to date. With respect to the optical discovery date, the first radio flare rises faster than $F_{\rm ν} \sim t^{9}$ at $Δt = 88-131$ days, and then decays as fast as $F_{\rm ν} \sim t^{-6}$. The emergence of a second radio flare is observed at $Δt \approx 194$ days with an initial fast rise of $F_{\rm ν} \sim t^{18}$, and an optically thin decline of $F_{\rm ν} \sim t ^{-12}$. We interpret these observations in the context of a self-absorbed and free-free absorbed synchrotron spectrum, while accounting for both synchrotron and external inverse-Compton cooling. We find that a single prompt outflow cannot easily explain these observations and it is likely that either there is only one outflow that was launched at $Δt \sim 80$ days, or two distinct outflows, with the second launched at $Δt \sim 170-190$ days. The nature of these outflows, whether sub-, mildly-, or ultra-relativistic, is still unclear, and we explore these different scenarios. Finally, we find a temporal coincidence between the launch time of the first radio-emitting outflow and the onset of a power-law component in the X-ray spectrum, attributed to inverse-Compton scattering of thermal photons.
format Preprint
id arxiv_https___arxiv_org_abs_2508_03807
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The First Radio-Bright Off-Nuclear TDE 2024tvd Reveals the Fastest-Evolving Double-Peaked Radio Emission
Sfaradi, Itai
Margutti, Raffaella
Chornock, Ryan
Alexander, Kate D.
Metzger, Brian D.
Beniamini, Paz
Duran, Rodolfo Barniol
Yao, Yuhan
Horesh, Assaf
Farah, Wael
Berger, Edo
J., Nayana A.
Cendes, Yvette
Eftekhari, Tarraneh
Fender, Rob
Franz, Noah
Green, Dave A.
Hammerstein, Erica
Lu, Wenbin
Wiston, Eli
Bernstein, Yirmi
Bright, Joe
Christy, Collin T.
Cruz, Luigi F.
DeBoer, David R
Golay, Walter W.
Goodwin, Adelle J.
Gurwell, Mark
Keating, Garrett K.
Laskar, Tanmoy
Miller-Jones, James C. A.
Pollak, Alexander W.
Rao, Ramprasad
Siemion, Andrew
Sheikh, Sofia Z.
Shoval, Nadav
van Velzen, Sjoert
High Energy Astrophysical Phenomena
We present the first multi-epoch broadband radio and millimeter monitoring of an off-nuclear TDE using the VLA, ALMA, ATA, AMI-LA, and the SMA. The off-nuclear TDE 2024tvd exhibits double-peaked radio light curves and the fastest evolving radio emission observed from a TDE to date. With respect to the optical discovery date, the first radio flare rises faster than $F_{\rm ν} \sim t^{9}$ at $Δt = 88-131$ days, and then decays as fast as $F_{\rm ν} \sim t^{-6}$. The emergence of a second radio flare is observed at $Δt \approx 194$ days with an initial fast rise of $F_{\rm ν} \sim t^{18}$, and an optically thin decline of $F_{\rm ν} \sim t ^{-12}$. We interpret these observations in the context of a self-absorbed and free-free absorbed synchrotron spectrum, while accounting for both synchrotron and external inverse-Compton cooling. We find that a single prompt outflow cannot easily explain these observations and it is likely that either there is only one outflow that was launched at $Δt \sim 80$ days, or two distinct outflows, with the second launched at $Δt \sim 170-190$ days. The nature of these outflows, whether sub-, mildly-, or ultra-relativistic, is still unclear, and we explore these different scenarios. Finally, we find a temporal coincidence between the launch time of the first radio-emitting outflow and the onset of a power-law component in the X-ray spectrum, attributed to inverse-Compton scattering of thermal photons.
title The First Radio-Bright Off-Nuclear TDE 2024tvd Reveals the Fastest-Evolving Double-Peaked Radio Emission
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2508.03807