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•Question 11 (1 point) An elliptical
galaxy could
•a. evolve into an irregular galaxy when it has used
up all of its gas and dust.
•b. be formed from the collision and merger
of spiral galaxies.
•c. become a starburst galaxy if it were to move
through the hot intergalactic
medium of a cluster.
•d. evolve from a single spiral galaxy when that
spiral used up all of its
gas and dust.
•Elliptical galaxies have already used up their gas
and dust, and it is thought
they can be formed from spiral mergers.
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•Question 12 ( 1 point) If a galaxy has a
radial velocity (redshift) of 5000
km/s, how far away is it? Assume a Hubble Constant of 70 km/s/Mpc.
a.7 Mpc b.20 Mpc c.49
Mpc d.71 Mpc e.100 Mpc
•V = Hxd, so d = v/H = 5000 km/s/70 km/s/Mpc – the
km/s cancel out to give
5000/70 Mpc = 71 Mpc
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