AstroNote 2025-14

We report here a radio detection of the tidal disruption event (TDE) AT 2024tvd (Sollerman et al. 2024; TNS discovery report 2024-3166, Faris et al. 2024; TNS classification report 18377) with the Karl G. Jansky Very Large Array (VLA) as part of our dedicated program for TDEs (24A-386; PI: Alexander). Careful assessment of the ZTF median position of this TDE shows that it is ~1’’ northeast from the nucleus of its host galaxy (Yao et. al AstroNote 2025-13). This makes AT 2024tvd the first off-nuclear TDE selected from modern sky surveys.

We conducted our observation on January 3, 2025, about 131 days after optical discovery, while the VLA was in its most extended A-configuration. Calibrations and imaging were performed in CASA, using the VLA calibration pipeline, with 3C286 as a bandpass and absolute flux calibrator, and J1735+3616 as the phase calibrator. Our observation in X-band (with a central frequency of 10 GHz) results in an image rms of ~10 uJy/beam and we detect a 600 +/- 60 uJy point source (including 10% calibration uncertainties) at R.A.: 17:10:42.571 +/- 0.002s, Dec.: +28:50:15.064 +/- 0.025’’ (J2000), which is ~0.05’’ from the reported position of the optical transient. The uncertainties on the R.A. and Declination correspond to 10% of the synthesized beam FWHM which is 0.26’’ and 0.21’’ on the major and minor axes, respectively. We also detect a 50 +/- 11 uJy source at R.A. 17:10:42.542 +/- 0.002s, Dec.: +28:50:14.293 +/- 0.025’’, less than 0.1’’ from the position of the center of the host galaxy seen in DESI Legacy Imaging Survey. This confirms the existence of an off-nuclear TDE, 0.9’’ from its galactic center, corresponding to a physical offset of 0.9 kpc at the host redshift of z = 0.045. Assuming a luminosity distance of 200 Mpc, the 10 GHz luminosity is ~3e38 erg/s, consistent with the radio luminosity of other non-jetted TDEs, e.g. ASASSN-15oi (Horesh et al. 2021), AT2019dsg (Stein et al. 2021, Cendes et al. 2021), and AT2020opy (Goodwin et al. 2022).

We plan to continue monitoring this source, and encourage further multi-wavelength observations.

We thank the VLA and the NRAO staff for scheduling and performing this observation.