Asymmetrical line profiles of He ii 304 Å line at nine positions across the 201-point field of view. The blue line shows the cumulative profile from ten unaligned threads with randomly generated velocities. The dashed red line shows the profile of a singular, stationary thread. The intensity is given in 10⁴ erg s^-1 cm^-2 sr^-1 Å^-1. The horizontal axis gives the distance from line centre Δλ in Å.