GCN Circular 37867
Subject
GRB 241001A: JWST spectroscopic identification of a supernova counterpart
Date
2024-10-25T08:20:10Z (5 months ago)
From
Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk>
Via
email
B. P. Gompertz (U. Birmingham), A. J. Levan (Radboud Univ. and Warwick Univ.), D. B. Malesani (DAWN/NBI and Radboud Univ.), B. Schneider (MIT), L. Izzo (INAF-OACn & DARK/NBI), T. Laskar (University of Utah) and A. Martin-Carrillo (UCD) report for a larger collaboration:
We obtained spectroscopic observations of the optical counterpart (Izzo & Malesani., GCNs 37667 and 37673; Breeveld et al., GCN 37678; Turpin et al., GCN 37679; SVOM/VT commissioning team, GCN 37695) to the SVOM/ECLAIRs-detected GRB 241001A (SVOM/ECLAIRs Commissioning Team; GCN 37655) at redshift z = 0.57 (Palmerio et al., GCN 37677) with the James Webb Space Telescope (JWST). Observations were carried out using the NIRSpec instrument on 2024-10-23, 21.5 days after trigger (13.7 days in the GRB rest frame). The total integration time was 1.7 hours with the clear prism in the wavelength range 0.5 - 5.5 µm.
The trace reveals a blue spectrum showing multiple broad absorption/emission features, similar to those observed in broad-lined type-Ic SNe commonly associated with long-duration GRBs. In particular, the spectrum matches well the one of GRB980425 / SN1998bw at 14 - 21 rest-frame days after collapse (Patat et al. 2001, Apj, 555, 900).
We acknowledge excellent support from Diane Karakla and Amber Armstrong (both STScI) in preparing these observations.