TITLE:   GCN CIRCULAR
NUMBER:  39779
SUBJECT: GRB 250314A: ATCA radio upper limits 
DATE:    25/03/19 13:49:11 GMT
FROM:    Tao An at SHAO, CAS <antao@shao.ac.cn>

Tao An, Yuanqi Liu, Kexuan Chong (SHAO), Jinjun Geng, Xuefeng Wu (PMO), report on behalf of a large collaboration: 

We have conducted radio observations of the high-redshift gamma-ray burst GRB 250314A (GCN 39719, 39729; redshift z ~ 7.3, GCN 39732, 39743) using the Australia Telescope Compact Array (ATCA). Our observations were performed on 2025 March 18 from UT 13:00 to 19:00, simultaneously at central frequencies of 5.5 GHz and 9 GHz. The achieved 1-sigma image rms noise levels are approximately 13 microJy/beam at 5.5 GHz and 9 microJy/beam at 9 GHz. At the position of the potential optical counterpart reported in GCN 39727, we find no significant radio emission above a 3-sigma threshold at either frequency.

We thank Jamie Stevens for his rapid response in scheduling these observations.

We thank the CSIRO Space and Astronomy staff for supporting these observations. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO.