|
|
|
|
|
|
|
|
|
|
|
|
• |
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
|
|