ALMA 3 mm observations of XS55. Top: ALMA 3 mm spectrum of XS55. The red line shows the line-free continuum, and the dotted blue line indicates the flux error per channel at a 1σ level. The spectroscopic redshift is shown in text, along with the velocity width of the channels. Bottom left: Velocity space spectrum of CO(5-4) (blue) and [CI](1-0) (red) at z = 4.8214, the uncertainty per channel is shown as dashed lines. Bottom right: Continuum and continuum-subtracted moment-0 line maps of XS55. Contour levels are 5, 8, and 11σ for the continuum, and 3, 4, and 5σ for the line maps. The beam size is shown as a white ellipse, and the peak JWST/F444W position is marked by a grey cross.