Exam 17: The Cosmic Web: the Large-Scale Structure of the Universe

Two spiral galaxies collide with each other in the outskirts of a galaxy cluster.After a long time,what will the combined system look like?

Why are distant galaxies' spectra redshifted?

Which of the following configurations is most likely to produce an Einstein ring?

What is the most likely source of the hot gas halos (with temperatures of 10 million K)within galaxy clusters?

Which of the following is NOT a likely consequence of the merger of two spiral galaxies?

Why are quasars rare today?

Suppose that heavy elements were common in the clouds that would form the first stars during the Dark Ages.How would the history of our Universe be different?

Why were quasars most common 10 billion years ago?

Imagine that astronomers in an alternate universe discover that galaxies at all distances from the Milky Way have similar luminosities,stellar properties,and structures.Which of the following is most likely to follow in this universe?

The Sloan Digital Sky Survey is most famous for:

What is the minimum scale on which the Universe becomes homogeneous?

Which of the following accurately characterizes the state of most of the hydrogen in the Universe from the time of Big Bang nucleosynthesis to the present day?

An astronomer observes many galaxies in distant parts of the sky to have emission lines redshifted relative to the same lines seen in a laboratory.What is the most likely explanation?

Which of the following astronomical objects has the largest look-back time?

The high temperature and pressure of gas in the intracluster medium of galaxy clusters implies that:

How would the history of structure formation in our Universe have been different if dark matter were not cold,but moved at a moderately fast velocity?

Why are neutrinos NOT a good candidate for cold dark matter?

Imagine that the expansion of the Universe proceeds at a constant rate at later times.How will the redshift of a particular galaxy change?

Which of the following techniques could allow astronomers to observe the structures in the Universe during the Dark Ages?

The figure below shows a schematic view of several galaxies in today's Universe,with an imaginary grid overlaid on top of them.If an astronomer drew a picture of this same system in 10 billion years,how would the picture differ?