GRB 211023A: BTA spectroscopic redshift
Abstract
We observed the afterglow of GRB 211023A (Zhirkov et al, GCN 30977, see also Kann et al, GCN 30982; Hu et al, GCN 30990; Belkin et al, GCN 31004; Vinko et al, GCN 31008; Belkin et al, GCN 31018; Belkin et al, GCN 31020; Kumar et al, GCN 31023; Gupta et al., GCN 31041; Strobl et al., GCN 31042) with BTA SAO RAS telescope equipped with SCORPIO-2 (VPHG940@600 grism). A total of 7200 s (6x1200 s) of spectra were obtained starting on 21-11-05 (UT) 20:50:00, i.e. approximately 13.3016 days after burst. The afterglow is well detected in the acquisition imaging with R = 21.61 +/- 0.04 (3 x 90 sec. 21-11-05 (UT) 20:43:59 -- 20:50:58), and a continuum is visible across the bandwidth of a spectrum 4000 - 8500 A. The spectrum contain significant emission lines H_beta, [OII] 3727, [OIII] 5007, at a common redshift of z=0.390. We assume that the lines are from a host galaxy and, therefore, this is the redshift of GRB 211023A. No evident lines of a possible SN were found. Calibration of photometry is preliminary and based on nearby stars of PS1 catalogue, gri -> R by Lupton transformations. We are grateful to the directorate of SAO RAS for the TOO allocation.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- November 2021
- Bibcode:
- 2021GCN.31053....1P