Top: deep LRIS spectrum of Q1549-C25. The spectrum is presented in the observed frame, and the flux-density units are μJy. The error spectrum is plotted in red. Blue- and red-side spectra are joined together at the 5000 Å dichroic cut-off. Top left: the top panel shows the LyC range (880−910 Å), indicated as a blue shaded region, and Lyman-series absorption lines. f₉₀₀ is evaluated as the mean flux density in the LyC region. The bottom panel shows the spectral range longward of Lyα, containing several labeled interstellar metal absorption lines. Top right: zoomed-in spectrum of Lyα emission. The Lyα profile profile is characterized by a single emission peak offset relative to the systemic redshift of Q1549-C25, indicated by the vertical dotted line. Bottom: two-dimensional spectrum of Q1549-C25, with the LyC region bracketed by vertical blue lines at rest wavelengths of 880 and 910 Å. Wavelength increases from left to right and the spatial scale is indicated with a vertical bar of 5″ in extent. The spectrum has been lightly smoothed by a Gaussian kernel with a 3 pixel radius.