Optical spectrum of G1 obtained using MagE on the Magellan Clay Telescope. The data reveal numerous emission features (marked by long dashed lines) with a mean redshift at z = 0.4188 ± 0.0001. The corresponding 1σ error spectrum is shown in cyan at the bottom above the zero flux level (dash–dotted line). Contaminating sky residuals are dotted out for clarification.