•A
range of structural types (Abell)
–Regular
indicates cluster is circular, centrally concentrated (cf.
Globular clusters), and has mostly elliptical and S0
galaxies. Can be very rich
with > 1000 galaxies. Coma is
regular.
–All
others are irregular (e.g., Virgo).
–I
don’t know why he didn’t just call them type 1 and
type 2…! /sarcasm
–