3
Spectroscopy of Ellipticals
•Rotation (V) and velocity dispersion (σ) curves for some ellipticals (Davies et al. 1983)
Note in particular:
Measurements do not extend as far as for
spirals, and peak velocity is near r = 2kpc, with slow decrease outside this
distance.
If there is rotation, how can one figure out the projection angle?
What can we tell about the shape of ellipticals from this information?