Measuring Non-axisymmetry in Spiral Galaxies
Remco Schoenmakers carries out a PhD project which examines the
deviations from axial symmetry in the potential of spiral galaxies.
Schoenmakers, Franx, van Albada and de Zeeuw developed a method to
measure deviations from axisymmetry in the kinematics of the HI disks of
spiral galaxies. The method consists of a tilted-ring fit in order to
decompose the velocity field of the galaxy into individual rings
followed by a harmonic fit to each ring. The Fourier terms found in
this way are interpreted in the context of non-axisymmetry of the
potential of the spiral galaxy. This method will be applied to a sample
of WHISP galaxies to retrieve systematics in the non-axisymmetry of the
potential of spiral galaxies.