Across
- 2. any atom heavier than helium.
- 3. nearly always a relatively old star found in the halo, globular clusters, or the nuclear bulge of a galaxy.
- 7. The linear relation between the distance to a galaxy and its radial velocity.
- 9. Object used to map the spiral arms
- 10. symmetrical spiral arms reaching out from the galaxy's central nucleus.
- 12. A region of the galaxy’s disk in which gas heated by supernova explosions throws gas out
- 13. A unit of distance equal to 1 million pc.
- 14. A cluster containing more than 1000 galaxies, mostly elliptical, scattered over a volume about 3 in diameter.
- 15. The effect of the focusing of light from a distant galaxy or quasar by an intervening galaxy to produce multiple images of the distant body.
Down
- 1. The conjecture that spiral arms in disk galaxies are caused by a pressure wave that rotates slowly around the galaxy
- 4. The process by which the birth of stars compresses the surrounding gas clouds and triggers the formation of more stars
- 5. the measured quantities would classify the Milky Way as a flocculent spiral galaxy
- 6. nearly always a relatively young star found in the disk of a galaxy.
- 8. Long, spiral pattern that extends from the center to the edge of the disk of spiral galaxies.
- 11. The combined calibration of distance indicators used by astronomers to find the distances to remote galaxies.