Question

1. When quasars were first discovered, why did astronomers conclude they were very distant objects?

   	A.	They were obviously in galaxies known to be very distant
   	B.	They had high redshifts
   	C.	They were extremely bright
   	D.	They were surrounded by very old stars

10 points   

QUESTION 7

1. What is a tidal tail?

   	A.	A jet of hot plasma emitted by an active galactic nucleus
   	B.	A stream of stars resulting from a galactic merger event
   	C.	A dust lane in a spiral galaxy
   	D.	The remnant of a planet destroyed by a collision with a star

2. QUESTION 4

3. The high luminosity of an active galactic nucleus comes from

   	A.	Intense radiation emitted from the black hole event horizon via Hawking radiation
   	B.	Bright, young, massive stars collected at the center of the galaxy
   	C.	Collisions between neutron stars
   	D.	Radiation from the hot gas in an accretion disk around a supermassive black hole

4. 10 points   

   QUESTION 5

5. In galaxy clusters, most of the galaxies appear to be elliptical galaxies because

   	A.	When galaxies collect in clusters, the proximity makes them puffier
   	B.	They aren't really elliptical, but they look that way because they are very distant
   	C.	Galaxies in clusters probably had many merger events in the past
   	D.	They formed in-situ from low-angular-momentum clouds

Answer 1