Galactic outflows are believed to play a critical role in the evolution of galaxies by regulating their mass build-up and star formation¹. Theoretical models assume bipolar shapes for the outflows that extend well into the circumgalactic medium (CGM), up to tens of kiloparsecs (kpc) perpendicular to the galaxies. They have been directly observed in the local Universe in several individual galaxies, for example, around the Milky Way and M82 (refs. ^(2,3)). At higher redshifts, …