Radio detection of the tidal disruption event AT2022wtn
ATel #15972; Collin T. Christy (Arizona), Kate D. Alexander (Arizona), Tanmoy Laskar (Utah), Edo Berger (Harvard), Adelle J. Goodwin (ICRAR-Curtin), James C. A. Miller-Jones (ICRAR-Curtin), Ryan Chornock (Berkeley)
on 31 Mar 2023; 18:25 UT
Credential Certification: Collin Christy (collinchristy@arizona.edu)
Subjects: Radio, Tidal Disruption Event
We report new radio observations of the tidal disruption event (TDE) AT2022wtn taken as part of our VLA Large Program dedicated to TDEs. AT2022wtn was first discovered as ZTF22abkfhua on 2022 October 2 as an optical flare (TNS Astronomical Transient Report No. 160738 by ZTF). It was later classified on 2022 November 21 as a TDE at a redshift of z=0.049 (TNS Classification Report No. 13873).
We observed AT2022wtn with NSF's Karl G. Jansky Very Large Array (VLA) on 2023 January 7.90 UT and 2023 March 20.67 UT at a mean frequency of 15 GHz. We reduced the data in CASA using standard procedures. We report the detection of a point source at 15 GHz (Ku band) with coordinates (RA, Dec) 23:23:23.79, +10:41:07.75, and a positional uncertainty of 0.04 arcseconds in each coordinate. This emission is coincident with the optical coordinates of AT2022wtn. In our first epoch, we marginally detected radio emission with a flux density of 20 +/- 7 μJy. In our second observation, the source had brightened to 223 +/- 6 μJy, confirming the transient nature of the emission and its association with the TDE. Further VLA radio observations to constrain the broadband spectrum of the source have been scheduled. We encourage additional multi-wavelength follow up.
Our VLA Large Program (20B-377) began in December 2020 and will continue until October 2023. We are targeting new publicly-reported TDEs discovered at z < 0.1, to determine the prevalence of radio emission in TDEs. We will report new results from this program to the community via ATels, TNS AstroNotes, and on our program website (https://www.as.arizona.edu/radiotdes). For collaboration, or to suggest new targets, please contact the program PI (Kate Alexander, kdalexander@arizona.edu) or one of the program co-Is.
