Long-slit spectra obtained with MISTRAL at the 1.93 m OHP telescope. The Hα lines of region D (red spectrum) and the position of the orthogonal projection of region D on the major axis of the galaxy (blue spectrum) are fitted by Gaussian functions, with intensities in normalised units. The two vertical dashed lines on Hα indicate the measured velocity of region D (1458±46 km s⁻¹) and on the disc (1629±46 km s⁻¹).