HI kinematics and dynamics of Messier 31

Understand

[Abridged] We present a new deep 21-cm survey of the Andromeda galaxy, based on high resolution observations performed with the Synthesis Telescope and the 26-m antenna at DRAO.

• The HI distribution and kinematics of the disc are analyzed and basic dynamical properties are given.
• The rotation curve is measured out to 38 kpc, showing a nuclear peak, a dip around 4 kpc, two distinct flat parts and an increase in the outermost regions.
• Except for the innermost regions, the axisymmetry of the gas rotation is very good.