Kinematics and dynamics of the central region in the barred galaxy NGC 1365

Abstract

We report observations of the Hα emission lines in the barred galaxy NGC 1365 using the TAURUS imaging Fabry–Perot interferometer. Although the resulting velocity field shows a number of gaps due to the absence of emission substantial non-circular streaming motions are clearly present. Within the bulge (∼2 kpc) gas streaming is on slightly elongated orbits oriented perpendicular to the bar, whereas in the bar region (∼2–10 kpc) gas streaming is on highly elongated orbits oriented along the bar. This is consistent with a picture of NGC 1365 as a rapidly rotating strong bar with a centrally concentrated bulge such that the inner Lindblad resonance is at ∼1.5 kpc and corotation somewhat beyond the end of the bar (∼10–15 kpc). Weak evidence is found for the expected shocks on the leading edge of the bar.