GCN Circular 31417
Subject
GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
Date
2022-01-09T04:04:47Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang, S.Y. Fu (NAOC), Z.P. Zhu (NAOC, HUST), X. Liu, D. Xu (NAOC),
X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220107B detected by Fermi (Arimoto et al.,
GCN 31409; Veres & Meegan, GCN 31414) and AstroSat (Suresh et al., GCN
31412), using the NEXT-0.6m telescope located at Nanshan, Xinjiang,
China. We obtained 6x300 s frames in the Sloan r-band and 5x300 s frames
in Sloan z-band, starting at 21:30:31 UT on 2022-01-08.
No optical source is detected in our stacked images at the Swift-XRT
position (Gropp et al., GCN 31411). Preliminary photometric results are
as follows:
Tmid-T0 (hr) Filter Upper Limit(5-sigma)
26.97 r >21.3
27.44 z >19.3
calibrated with the nearby PanSTARRS field.
In addition, from Legacy Survey there exists a faint source at the
border of the Swift-XRT error circle at coordinates R.A. (J2000) =
14:25:37.66 and Dec. (J2000) = +20:10:17.01, and magnitudes of g ~
24.62, r ~ 24.51, z ~ 23.32 as well as a photo_redshift = 1.13 +/- 0.23.
The source is not present in SDSS and PanSTARR, and might be the host of
the burst.