Exam 25: Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Describe how gravitational lensing works. What can it tell us about a quasar? What can it tellus about the galaxy that is doing the lensing? How is lensing valuable to the study of darkmatter?

A great advantage of using ________ to map the universe is that it detects distributions ofboth normal and dark matter.

Based on observations of the bullet cluster, what happens to the hot gas, the dark matter, andthe luminous portions of clusters during collisions?

Star streams that are seen around the Milky Way Galaxy are probably the result of:

Active galaxies are having their central engines temporarily fed by what occurrence?

Most large spirals and ellipticals are comparable to the Milky Way in mass.

An interaction between a large and a small elliptical galaxy that results in a large spiral and asmall elliptical galaxy takes:

When two galaxies move very closely to each other, their ________ may dramaticallyrearrange their visible structures.

The cosmological principle calls for the distribution of galaxies to be homogeneous. On thelarge scale, is this true?

The further away a galaxy is:

Due to the galaxy density and collisions, ________ are rare in the centers of clusters.

The lensing of a distant quasar is produced by ________ of a foreground galaxy.

Based on galactic rotation curves and cluster dynamics, we think dark matter:

A billion solar mass black hole has a radius of only:

The largest voids may span 300 million light-years across.

Giant irregulars are the most massive of all known galaxies.

What is true of spiral galaxies?

How massive are the largest known galaxies?

All of the following are clusters of galaxies EXCEPT:

The type of radio galaxy that reveals its motion through the intergalactic medium is called a: