Chapter 28: The Large Scale Structure of the Universe

Question 1

What are standard candles?

Answer 1

objects whose known intrinsic characteristics can be used to determine distance (Cepheid, Supernovae)

Question 2

What is the cosmic distance ladder?

Answer 2

top-down = hubble law, supernovae, Tully-fisher, cepheids, spectroscopic parallax, stellar parallax, radar ranging

Question 3

What is Hubble Law?

Answer 3

All galaxies seem to be moving away from us. The redshift of their motion is correlated with their distance. (like a rubber band)

Question 4

What is the local group of galaxies?

Answer 4

about 54 galaxies within 1Mpc of the milky way (3 spirals = us, andromeda and M33)

Question 5

What is the virgo cluster?

Answer 5

larger than the local group (2000+ galaxies) spans over 10 degrees on the sky (3Mpc)

Question 6

What is the local supercluster?

Answer 6

20 Mpc, clusters of galaxies

Question 7

What is the coma cluster?

Answer 7

100 Mpc away

Question 8

What is a cluster of galaxies?

Answer 8

Large collections of thousands of galaxies

Question 9

What are superclusters of galaxies?

Answer 9

Clusters and groups bunch together, larger than 30 Mpc, tens to hundreds of thousands of galaxies

Question 10

What is the Hubble Deep Field?

Answer 10

11-day exposure of a narrow pencil beam of the sky (10,000 galaxies) reveals the evolution of galaxies

Question 11

Dark Matter in galaxies

Answer 11

must provide the clumpiness in the universe for structures to form around