Exam 23: Large-Scale Structure in the Universe

Explain how computer simulations of structure formation and observations of the structure in the universe today can help astronomers determine the nature of dark matter.

Figure 1 -Figure 1 shows images taken from the Bolshoi simulation of the formation of the large-scale structure in the universe. Which one of these images shows the current structure of the universe?

In the early universe, why were inhomogeneities in the distribution of normal matter much smaller than the inhomogeneities in the dark matter?

What does the large-scale structure of the universe look most like?

Which of these components makes up the largest amount of mass in a typical large cluster of galaxies?

Which of these shows the correct order of collections of galaxies, starting with the smallest and ending with the largest?

As structure formed in the universe, galaxy-sized objects formed before cluster-sized objects.

Astronomers have determined that the Milky Way is being pulled toward a massive structure called the "Great Attractor" due to the mass of the Great Attractor alone.

The Local Group is a part of the Virgo Supercluster.

Even at its earliest moments, the universe had about as much structure in it as it has at the current time.

Which is NOT an ingredient needed to build a cosmological simulation of large-scale structure formation?

The figure below shows a diagram separating out the different eras of the universe based on the events that occurred during that era. Each era is labeled by a different letter. Which of the sections of the image represents the dark era?

The figure shown below shows two different versions of the Hubble tuning fork diagram. One was made using what galaxies are like now, while the other was made using what galaxies were like 6 billion years ago. Which one was made using observations of what galaxies were like 6 billion years ago?

How do we know how fast the Milky Way is moving relative to the local universe? What are we moving toward, and what do we think is mostly responsible for this motion?

Explain why a galaxy can collapse to a much smaller size than its dark matter halo.

Peculiar velocities are produced by:

The peculiar velocities of galaxies allow us to determine how matter is distributed in the universe.

If neutrinos have mass but do not interact much with normal matter, why can't they be the dominant form of dark matter in the universe?

What is the fundamental difference between the two basic types of dark matter? List an example of each type.

Which of these statements about galaxy clusters is true?