Velocity profiles of Ca ii λ3934,3969 absorption in the DLA at z_abs = 0.312710 toward PKS 1127−145. The velocities of the five galaxies belonging to the galaxy-group at z_abs = 0.313 along the PKS 1127−145 sightline (Kacprzak et al. 2010b) are indicated in blue. The horizontal lines indicate the velocity range allowed for the individual galaxies based on a simple disk-rotation scheme for these galaxies (Kacprzak et al. 2010a).