Exam 17: Hubbles Law and Dark Matter: the Large-Scale Structure of the Cosmos

Mapping the intracluster gas is largely done with red light from the ionized emission lines of hot hydrogen.

As we look at larger and larger scales in the universe, we find

On a large scale, we find the universe to have voids and structure.

A galaxy that was once a quasar is likely to

According to our HST deep surveys, which of the below are NOT less common now than in the early universe?

Why is the Chandra X- ray Observatory critical to mapping intracluster gas?

Because of the great masses and speeds involved, Newton's laws are useless in measuring the mass of a galaxy.

What is true of spiral galaxies?

Why did the quasar epoch end?

What is believed to be the large- scale structure of the universe?

There is presently no evidence for large- scale structure bigger than about 200 Mpc.

From studies of the rotations of galaxies and dynamics of clusters, we now think that about of the mass of the universe is composed of dark matter.

Both spiral and elliptical galaxies seem to have dark halos of similar proportions relative to their visible matter.

Describe the large- scale structure revealed by the redshift surveys.

The absorption lines we find in quasar redshifts that arise from intervening gas clouds show even larger redshifts than the quasar spectra, due to dust absorption.

The absorption or accretion of smaller galaxies into larger ones is called .

If the merger theory is correct, the brightest active galactic nuclei should

The Andromeda galaxy will eventually collide with the Milky Way.

A radio galaxy whose lobes are swept back as if forming a tail probably indicates

The largest presently known redshifts of quasars are close to