[vsnet-grb-info 21900] GRB 190324A: VLT/X-shooter redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23999
SUBJECT: GRB 190324A: VLT/X-shooter redshift
DATE:    19/03/25 02:59:34 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani at dark-cosmology.dk>

D. A. Perley (LJMU), L. Izzo (HETH/IAA-CSIC), D. A. Kann 
(HETH/IAA-CSIC), D. B. Malesani (DAWN/NBI and DARK/NBI) report on behalf 
of the Stargate collabaration:

We observed the optical afterglow (Marshall, GCN 23996) of GRB 190324A 
(LaPorte et al., GCN 23993) using the ESO VLT UT2 (Kueyen) equipped with 
the X-shooter spectrograph. Our spectra cover the wavelength range 
3000-21000 AA, and consist of 2 exposures by 600 seconds each. The 
observation mid time was 2019 Mar 25.0441 UT (2.324 hr after the GRB).

We detect continuum at high-S/N over the entire covered wavelength 
range. A multitude of absorption features are detected, including Ca II, 
Mg II, Mg I, Fe II, Al II, Cr II, all at a common redshift z = 1.1715. 
In particular, fine structure lines from Fe II* are visible, which 
confirm the association of the absorption system with the GRB.

We acknowledge excellent support from the ESO observing staff in 
Paranal, in particular Romain Thomas, Anita Zanella, and Juan Carlos 
Olivares.