Radio detection of the TDE AT 2021sdu at 5.1 GHz with e-MERLIN
ATel #15097; Javier Moldon (IAA-CSIC, Granada), Miguel Perez-Torres (IAA-CSIC, Granada), Erik Kool (Stockholm University), Seppo Mattila (University of Turku), Thomas Reynolds (University of Turku)
on 9 Dec 2021; 15:29 UT
Credential Certification: Javier Moldon (jmoldon5@gmail.com)
Subjects: Radio, Transient, Tidal Disruption Event
We report the radio detection of the tidal disruption event (TDE) AT 2021sdu with the electronic Multi-Element Radio Linked Interferometer (e-MERLIN) at 5.1 GHz. AT 2021sdu was classified as a TDE by ZTF (TNS Classification Report No. 10352). We observed AT 2021sdu with e-MERLIN on 4 November 2021 and 1 December 2021, and detected it in both epochs with flux densities of ~0.1 and ~0.2 mJy at 5.1 GHz, respectively. The observations provide accurate source localization with a synthesized beam size below 50 milliarcseconds.
These detections suggest that the emission at 5.1 GHz is rising towards its maximum. Our detection of AT 2021sdu on 4 November 2021 precedes the VLA detection at 18 GHz, at a level of ~0.7 mJy, reported by Alexander et al. (ATel #15091) by 24 days. Given the significantly higher level of emission at 18 GHz on 28 November 2021, and the observed increase of emission at 5.1 GHz between November 4 and December 1 with e-MERLIN, we deem it likely that the TDE emission at 18 GHz is currently around its peak of emission or past it. We will continue the monitoring with e-MERLIN under our TDE programme, using 5.1 and 1.5 GHz observations, and encourage further radio monitoring with other facilities.
We thank the e-MERLIN for supporting our observations and extend our thanks to the e-MERLIN staff for enabling these observations. e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC.
