•Should follow equations of stellar dynamics.
•Treat as “collisionless”
ensemble
•Relaxation time is important – this defines the
time between
“collisions”
•Work out energetically to get
•Trelax = V3/8πnG2m2log(R/b)
•V is mean
relative speed, n is stellar density, m is the mean stellar mass, R is radius of galaxy, and b is the minimum impact parameter.
•Details will probably be a homework problem.