AstroNote 2024-290

We observed the field of the Fast and Blue Optical Transient (FBOT) AT 2024wpp (Ho et al., AstroNote 2024-272) with the Allen Telescope Array (ATA) between UT 06:25:13.0 and 11:33:17.2 on October 9, 2024, about 13 days after the optical discovery. Our observation was carried out with two spectral windows centered around 3 and 8 GHz, each with a bandwidth of 672 MHz. Calibration and imaging were performed using CASA with 3C147 as a bandpass and absolute flux scale calibrator, and 0241-082 as a complex gain calibrator.

No radio emission was detected at the position of AT 2024wpp in both frequencies. The flux density upper limits (3 sigma image RMS) are 0.57 and 1.1 mJy/beam in 3 and 8 GHz, respectively. This translates to luminosity upper limits of ~1e+29 and ~2e+29 erg/s/Hz in 3 and 8 GHz, respectively, for a distance of ~400 Mpc (based on z=0.0868, Perley et al. Astro-note 2024-280). For comparison, 10 GHz observation of the FBOT AT 2020xnd showed a luminosity of ~4e28 erg/s/Hz, ~3 times fainter than our 3 sigma limits, at the same time since optical discovery (Bright et al. 2022).

The Allen Telescope Array refurbishment program and its ongoing operations are being substantially funded through the Franklin Antonio Bequest. Additional contributions from Frank Levinson, Greg Papadopoulos, the Breakthrough Listen Initiative and other private donors have been instrumental in the renewal of the ATA. Breakthrough Listen is managed by the Breakthrough Initiatives, sponsored by the Breakthrough Prize Foundation. The Paul G. Allen Family Foundation provided major support for the design and construction of the ATA, alongside contributions from Nathan Myhrvold, Xilinx Corporation, Sun Microsystems, and other private donors. The ATA has also been supported by contributions from the US Naval Observatory and the US National Science Foundation.