GCN Circular 44227
Subject
EP260321a: uGMRT observations
Event
Date
2026-04-07T11:11:53Z (10 days ago)
From
Aishwarya L Thakur at INAF-IAPS, Rome <aishth@outlook.com>
Via
Web form
G. Gianfagna (INAF-IAPS), A. Balasubramanian (IIA),
G. Bruni (INAF-IAPS), D. Eappachen (IIA),
L. Piro, A. L. Thakur (INAF-IAPS), G.C. Anupama, D.K. Sahu, Aru Beri (IIA), Varun Bhalerao, Aditya Pawan Saikia (IITB) report:
We observed the Fast X-ray Transient EP260321a (Huang et al, GCN 44068, GCN 44075) with the upgraded Giant Metrewave Radio Telescope (uGMRT). Observations were performed on March 26 2026 (at a mean epoch of ~5 days after the EP trigger) for a total of 2 hours in Band 5 under a joint allocation for programs 49_076 (PI Eappachen) and 49_114 (PI Gianfagna).
Data were reduced and imaged with the SPAM pipeline. The final image rms in Band 5 is ~90 uJy/beam.
We do not detect any radio emission at the position of the optical counterpart (Lipunov et al. GCN 44069, Lee et al. GCN 44070, Ma et al. GCN 44074, Aguilar-Ruiz et al. GCN 44076, Liang et al. GCN 44079, Aryan et al. GCN 44081, Tanvir et al. GCN 44082, Moran et al. GCN 44083, Ahumada et al. GCN 44084, Liu et al. GCN 44087, Sankar et al. GCN 44089, de Ugarte Postigo et al. GCN 44091, Xu et al. GCN 44092, Pankov et al. GCN 44103, Corcoran et al. GCN 44105, Rastinejad et al. GCN 44107, Gao et al. GCN 44110, He et al. GCN 44117, Zhang et al. GCN 44171).
The three-sigma upper limit on the radio counterpart is thus 270 uJy/beam at 1.1 GHz.
Additional uGMRT observations are planned.
We thank the staff of the GMRT who made these observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research.