Radio Detection of AT2019teq with the Very Large Array (VLA)
ATel #15728; Yvette Cendes (Harvard University), Kate Alexander (University of Arizona), Edo Berger (Harvard University), Ryan Chornock (University of California- Berkeley), Sebastian Gomez (STSCI), Aprajita Hajela (University of Copenhagen), Tanmoy Laskar (University of Utah), Raffaella Margutti (University of California- Berkeley)
on 29 Oct 2022; 15:31 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yvette Cendes (yvette.cendes@cfa.harvard.edu)
Subjects: Radio, Tidal Disruption Event
We report the discovery of late-time radio emission from the TDE AT2019teq with the Very Large Array (VLA). AT2019teq (z=0.0878) was discovered by the Zwicky Transient Facility (ZTF) on 20 October 2019 02:47:36 UT. Swift-XRT observations between December 2019 to May 2020 (55 - 200 days post discovery) revealed a soft X-ray spectrum with a powerlaw with an index of 3.52 (+0.53,-0.45; ATel #15657), and subsequent XMM-Newton observations in September 2022 (~1054 days after discovery) showed a similar X-ray spectrum with a best-fit powerlaw index of 2.99+-0.01 (ATel #15657). NICER observations on 18 October 2022 and 21 October 2022 showed a best fit powerlaw index was 1.82+/-0.12, indicating the spectrum has significantly hardened within <2 months and the X-ray corona may be actively forming (ATel #15724).
VLA observations were carried out from 18 October 2022 at 23:26:20.0 to 19 October 2022 at 00:26:05.0 (UTC) as part of an ongoing VLA program to study late-time TDE emission (22B-205). We report a detection at 6 GHz (C-band) of 0.238 +/- 0.008 mJy, consistent with the optical position. We reduced the data using standard CASA procedures. We note that two Very Large Array Sky Survey (VLASS) observations of the coordinates exist, both of which are upper limits: VLASS 1.2 (4 October 2017) was <0.310 mJy, and VLASS 2.2 (13 August 2020) was <0.329 mJy (both 3 sigma).
Further multi-frequency VLA observations are planned to study the time evolution of the radio emission. We thank the NRAO staff for supporting these observations.
