Fig. 7: MUSE spectra and HST maps for a selection of companion galaxies around W0410-0913.

a Lyman-α spectra of 3 among the Lyman-α-emitters discovered with MUSE in the surrounding environment of W0410-0913. These objects belong to the denser dynamic volume (with offset velocities in the range [−2.500; +1.500] km s⁻¹), have HST detections, and are selected to be representative of the high (left), median (center), and low (right) distribution of the Lyman-α flux SNR (see Table 1). Lyman-α spectra, extracted from circular regions with a radius of 1″ and centered around the Lyman-α peaks, are shown in gray. The wavelength range in the x-axis has a width of 120 Å and is centered around the central wavelength obtained through a Gaussian fit (Gaussian models are shown in blue). Legends report the redshift of each source (derived through Lyman-α), their FWHM, and their offset velocity with respect to the systemic redshift of the central luminous object. Gray shaded areas represent the regions affected by sky lines. A compilation of MUSE spectra for all the Lyman-α-emitting galaxies around W0410-0913 is shown in Supplementary Figs. 1 and 2. b HST cutouts (4″ × 4″) of the Lyman-α shown above, detected with the WFC3/F160W filter (colored images). The 2σ contours of pseudo-NB Lyman-α images obtained with MUSE are overlaid in black. Red dashed circles represent the circular apertures with 1″-sized radii that we use to extract the HST flux and estimate the SFR. The cutouts for all the HST-detected companion galaxies are shown in Supplementary Fig. 3.