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GCN Circular 33233

ZTF23aaarlti/AT2023avj: VLA radio detection
2023-01-29T17:46:54Z (a year ago)
Daniel Perley at Liverpool JMU <>
D. A. Perley (LJMU) and A. Y. Q. Ho (Cornell) report on behalf of a larger collaboration:

We observed the location of the fast optical transient AT2023avj (ZTF23aaarlti; Wang et al., GCN 33226 and AstroNote 2023-17) using the Karl G. Jansky Very Large Array (VLA) on 2023 January 28 between 06:48 and 07:28 (UT).  Observations were carried out using the X-band receivers at a mean frequency of 10 GHz.

We detect a strong source at a location of RA = 09:39:20.7894, Dec=+58:08:12.619 (J2000; RMS statistical accuracy +/- 0.01"), consistent with the optical position.  The flux density is 253 (+/-5) microJy at 10 GHz.  The mean observation time is approximately 59972.297, 6.0 days after the first reported optical detection.

The detection of radio emission supports the conclusion that the source is the afterglow of a relativistic explosion at cosmological distance.

We thank the VLA staff for rapidly scheduling and executing these observations.

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