TITLE:   GCN CIRCULAR
NUMBER:  44678
SUBJECT: GRB 260428A: TERI Gamma-ray detection
DATE:    26/05/21 14:02:09 GMT
FROM:    nicholasjkirschner@gmail.com

Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher
(c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c)
(a) National Research Council Research Associate resident at the U.S. Naval Research
Laboratory, 4555 Overlook Ave SW, Washington, DC 20375
(b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375
(c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA

The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on
the International Space Station, reports the detection of GRB 260411B, which was also detected
by Fermi GBM (GCN 44415), AstroSat (GCN 44421), GECAM-B (GCN 44423), and
SVOM/GRM (GCN 44424).

Using 1 Hz binning, and adopting T0 = 2026-04-28T14:20:34.992Z, we observe one peak at
T0+1.5s, with peak excess count rate of 49 above the 97 cps baseline rate observed in nearby offsource intervals.

The analysis results presented here are preliminary and currently lack a detailed response
function.

TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated
CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL)
in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV
to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space
Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility
on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval
Research 6.1.

[1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal
of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009
(arXiv:2408.04559).

Distribution Statement A: Approved for public release. Distribution is unlimited.