On UT 2022 Oct 02 the Very Large Array (VLA) observed the position of AT2022tsd, a fast optical transient coincident with a z=0.256 galaxy (Ho et al. AstroNote #2022-199). The Ku-band (central frequency 15 GHz) image RMS was 4 uJy in 45 minutes of on-source time.
A point source was detected within 0.2 arcsec of the optical position of AT2022tsd with a flux density of 25 uJy in Ku-band. At z=0.256 this corresponds to a luminosity of 5E28 erg/s/Hz at 30 observer-frame (24 rest-frame) days post-discovery. The luminosity is close to that of AT2018cow at a similar frequency and epoch (3E28 erg/s/Hz at 22 GHz at dt=22 days; Margutti et al. 2019, ApJ, 872, 18), and lower than that of AT2020xnd (2E29 erg/s/Hz at 15 GHz at dt=20 rest-frame days; Ho et al. 2022, ApJ, 932, 116).
Imaging the upper and bottom half of the band separately suggests that the emission is self-absorbed, as expected for a transient similar to AT2018cow at this epoch.
We thank the VLA staff for rapidly scheduling and executing these observations.
| Catalog | Name | Reported RA | Reported DEC | Reported Obj-Type | Reported Redshift | Host Name | Host Redshift | Remarks | TNS RA | TNS DEC | TNS Obj-Type | TNS Redshift |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TNS | 2022tsd | 03:20:10.868 | +08:44:55.96 | 03:20:10.863 | +08:44:55.63 | |||||||
| TNS | 2018cow | 16:16:00.220 | +22:16:04.91 | SN Ic-BL | 0 | 16:16:00.220 | +22:16:04.91 | SN Ic-BL | 0.014 | |||
| TNS | 2020xnd | 22:20:02.030 | -02:50:25.30 | 22:20:02.030 | -02:50:25.30 |
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