GCN Circular 36087
Subject
GRB 240414A: Redshift confirmation from GTC/OSIRIS+
Date
2024-04-14T07:07:37Z (a month ago)
From
Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>
Via
email
A. de Ugarte Postigo (CNRS, OCA, LAM), G. Lombardi (GRANTECAN), J. F. Agui Fernandez (CAHA), C. C. Thoene (ASU-CAS), J. P. U. Fynbo (DAWN/NBI), L. Izzo (INAF-OACn & DARK/NBI), N. R. Tanvir (U. Leicester), A. Martin-Carrillo (UCD), S. Geier (GRANTECAN) report:
We have obtained spectroscopy of the afterglow of GRB 240414A (Caputo et al. GCN 36083, Schneider et al. GCN 36084) with OSIRIS+ on the 10.4m GTC on the Roque de los Muchachos Observatory (Spain). The observation consisted of 3x900s exposure with grism R1000B covering the range between 3600 and 7880 AA at a mean epoch 2.11 hrs after the burst.
We detect a strong continuum over all the spectral range with absorption features that we identify as due to OI, CII, SiIV, SiII, CIV, AlII, NiII, AlIII, ZnII, FeII and MnII, as well as SiII* and FeII*, all at a common redshift of 1.833, consistent with the redshift determined by Adami et al. (GCN 36085).
Additionally, we identify an absorption system with CIV and MgII at z=1.703 and another one with MgII at z=1.067. Finally, there is a further strong and slightly broadened feature at 4056 AA that could be due to an intervening system of CIV at z=1.618, but there are no other related features to confirm it.