1. A(n) ____ emits large amounts of energy but photographically appears to be a single point of light much like a star.a. a planet like Venusb. E galaxyc. spiral galaxyd. double-lobed radio galaxye. quasar

2. Quasars must be small because theya. have high radial velocities.b. are very luminous.c. are surrounded by quasar fuzz.d. radiate huge amounts of energy.e. fluctuate rapidly on time scales as short as a few hours.

3. Seyfert galaxiesa. are more common in close pairs of galaxies than in isolated systems.b. emit more energy at X-ray, ultraviolet, infrared, or radio wavelengths than normal spiral galaxies.c. generally show red shifts greater than 6.d. a and be. a, b and c

4. How do astronomers know that the nuclei of some galaxies are active?a. Their nuclei are much brighter than expected.b. The orbits of stars near the center of the galactic nuclei are faster than expected.c. The luminosity of the nuclei varies over time.d. The color of the nuclei is different than expected.

5.How does the study of quasars reveal information of the history of the universe?a. Typical quasars are very distant so we can view how galaxy evolution occurred in the past.b. Quasars contain stars of all ages.c. Quasars typically act as host galaxies for gravitational lensing.d. Quasars generate their energy in very small volumes of space

6. The energy from an AGN is produced bya. the collision of two spiral galaxies.b. the collision of two elliptical galaxies.c. the collision of two radio jets.d. matter flowing into a supermassive black hole.e. supernovae.

7. The rotation curve of a galaxy can be used to determinea. the relative number of hot young stars in the galaxy.b. the relative amount of gas and dust in the galaxy.c. the radius of the galaxy.d. the luminosity of the galaxy.e. the mass of the galaxy.

8. Supermassive black holes are believed to be located at the center of many galaxies becausea. the rotation curve of the galaxy indicates that 90% of the galaxy is dark matter.b. the orbital motion of material near the center is very fast and indicates a very massive core.c. the shape of the bulge in all spiral galaxies can only be supported by a supermassive black hole.d. the spiral structure requires a black hole to maintain the spiral arms.e. the orbital speeds of a globular clusters in the galaxy are greater than the speed of light.

9. If Galaxy A is found to have a recessional velocity four times greater than Galaxy B, what can you say about their relative distances from Earth?a. Galaxy A is four times closer than Galaxy B.b. Galaxy A is four times further away than Galaxy B.c. Galaxy A is twice as distant than Galaxy B.d. Galaxy A is twice as close than Galaxy B.

10. Which of the following is the largest object?a. The Milky Way galaxy.b. The Large Magellanic Cloud.c. The Local Group.d. The Andromeda galaxy.

11. What is the Hubble constant essentially a measure of?a. The number of galaxies in the universe.b. The expansion of the universe.c. The age of the Milky Way galaxy.d. The amount of dark matter in an average galaxy.

12. The look-back time isa. the time it takes for the light from an object to reach Earth.b. numerically equal to the distance in light-years.c. smaller for more distant objects.d. all of the abovee. a and b above