9 Chapter 9 – What does the Universe look like?
OpenStax Astronomy Chapter 28: The Evolution and Distribution of Galaxies
Distribution of Galaxies
I. Galaxy
A. Galaxies are found in
1. collections of galaxies
2. Usually contain galaxies than spirals or ellipticals
B. : Smaller, less than about galaxies
1. The Milky Way is in the
a. giant (MW & Andromeda) and about dwarf galaxies
b. megaparsecs (6 million light years) in diameter
In the Local Group, there are more galaxies than galaxies.
A. Giant, dwarf
B. Dwarf, spiral
C. Spiral, elliptical
D. Giant, spiral
C. : contain of galaxies, megaparsecs in diameter
1. Milky Way is in a cluster, only in a group
2. Nearest clusters are Cluster and much larger Coma Cluster
3. Clusters also contain additional
D. clusters and groups bunch to form
1. Contain up to of galaxies
2. megaparsecs in size, over 10 times bigger than Local Group
E. : location in space in order of size
1. Earth,
II. of the Universe
A. Astronomers map distances of lots of galaxies to see the in the Universe
B. Superclusters form extended filaments or with of nothing in between
1. Analogy:
Which of the following lists the types of galaxy collections in order of increasing size:
A. Cluster, group, wall, supercluster
B. Cluster, supercluster, group, wall
C. Group, wall, cluster, supercluster
D. Group, cluster, supercluster, wall
Structure Formation
Section 28.1, Section 28.2, & Section 28.5
III. How
A. forms in universe due to gravity
B. Clump’s pulls in
1. Normal matter falls to the
C. from normal matter inside of (clump)
1. show the universe had mostly protogalaxies
D. formed from protogalaxy , like the Milky Way
E. galaxies in universe
F. In early universe, galaxies were together and galaxies sometimes from of galaxies
1. See ellipticals in big galaxy today
2. Also in early universe, likely by gas in galaxies
G. formed , then brought them together to form clusters, superclusters, and large-scale structure
Structure formation in our universe:
A. Begins with the largest structures first, and proceeds down to smaller ones
B. Begins with the smallest structures first and goes up to larger structures
C. Begins on all spatial scales at the same time
D. Begins after clusters form
What is most responsible for shaping the large-scale structure of the universe?
A. Supernovae from the first generation of stars
B. Magnetic fields
C. Atomic forces
D. Gravity
