Line-of-sight velocities v_LOS of the Hα emitters with the Ha_C filter used for the MSIS observations. The red line indicates the systemic velocity of NGC 2865 (2627 km s^-1, Smith et al. 2000). The distribution of the velocity of the seven intergalactic HII regions has a peak at 2711 km s^-1, which is very close to the systematic velocity of NGC 2865. The Gaussian distribution is plotted in blue has average velocity 2627 km s^-1 and σ = 200 km s^-1.