GRB 190719C: VLT/X-shooter spectroscopic redshift of the host galaxy

We observed the location of the candidate host galaxy (Malesani et al., GCN 25110; Heintz et al., GCN 25144) of GRB 190719C (Ambrosi et al., GCN 25106; Poolakkil & Meegan, GCN 25130) using the ESO VLT UT2 (Kueyen) equipped with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, and consist of 4 exposures by 600 s each. Our observations started on 2019 August 01 at 00:48:20 UT, ~13.4 days after the GRB detection. The slit was centred on the nucleus of the nearby object visible in the Pan-STARRS archival images, and was oriented in order to include the afterglow position. While only weak continuum is visible, several clear emission lines are detected in the near-infrared arm. We identify the [O ii] 3727/3729 doublet, Hbeta, [O iii] 4959, and [O iii] 5007, at a common redshift z = 2.469. No clear emission (lines nor continuum) is detected at the location of the afterglow, so we have no direct measurement of the GRB redshift. The random association probability with the Pan-STARRS object is however rather small (~3*10^-3), suggesting a physical connection. We also note that the Pan-STARRS galaxy is exceptionally luminous, with an absolute magnitude M = -22.9 AB (computed at 1800 AA rest frame). The measured offset would correspond to 6.6 kpc in projection - a rather large value but not surprising for such a bright host. In conclusion, we propose z = 2.469 as the redshift of GRB 190719C. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Gaspare Lo Curto, Marcela Espinoza, Boris Haeussler, Aleksandra Solarz, and Steffen Mieske.