Off-nuclear spectra can reveal whether the stellar velocity distribution is anisotropic and if so whether it is predominantly radial or tangential anisotropy. For predominantly tangential (e.g. circular) orbits, the LOSVD (absorption line profiles) are stubby (negative h4). Conversely, predominantly radial orbits yield more peaked LOSVD profiles (positive h4).
Four galaxies from the SAURON IFU survey of Ellipticals and S0s. The rows give various kinematic parameters, and the bottom row shows the h4 parameter. The ranges for each parameter are given at the side of each image. Note, for example, that NGC 3379 is colored red in the outer parts, showing positive h4 and hence velocity distributions dominated by radial orbits.