Lyα profile of COLA1 obtained from the VLT/X-shooter UV spectrum. We assume a systemic redshift of z = 6.59165, the average redshift measured in the NIRCam grism data in module A. The dashed (dot-dashed) color lines mark the position of the systemic Lyα wavelength suggested by the redshifts obtained from the centroids of [O III]_λ5008, [O III]_λ4960 and Hβ lines in module A (module B) of the WFSS data. For module A the variation in the horizontal direction is lower than the width of the marker lines.