Across
- 4. caused by a pressure wave that rotates slowly around the galaxy
- 5. irregularly shaped cluster that contains fewer than 1000 galaxies
- 7. linear relation between the distance to a galaxy and its radial velocity.
- 8. galaxies that have a fluffy appearance
- 12. A unit of distance equal to 1 million pc.
- 14. A region of the galaxy’s disk in which gas heated by supernova explosions
- 15. any atom heavier than helium.
Down
- 1. The cluster of about 40 nearby galaxies
- 2. spheroidal cloud of stars at the center of most spiral galaxies,
- 3. used by astronomers to find the distances to remote galaxies.
- 6. long strand of gas, dust, and stars drawn out of a galaxy
- 9. spiral pattern of bright stars, star clusters, gas, and dust
- 10. large galaxies absorb smaller galaxies
- 11. a thin scattering of stars, star clusters, and small amounts of gas.
- 13. A cluster containing more than 1000 galaxies