Forming Ellipticals
Ellipticals may be the "oldest" population of galaxies observed
today -- when and how do they form?
- spheroidal
- log I ~ r1/4 : sign of violent relaxation
(Lynden-Bell 1967)
- high internal random motions ( large sigma / vrot
)
All these point to a chaotic formation process: mergers?
Nearby example:
NGC 7252, from Hibbard etal 1994
What about at high redshift? What's going on there?