Exam 15: Galaxies and the Foundation of Modern Cosmology

Use the graph above showing data for the brightest galaxies in clusters of galaxies to answer the following questions. Which statement describes this graph?

Which of the following statements is an explanation, not an observation?

Galaxy collisions were more common in the past.

Approximately how many stars does a dwarf elliptical galaxy have?

How do quasars produce so much energy in such a small volume.

In a photo like the Hubble Deep Field (Figure 15.1 in your textbook), we see galaxies in many different stages of their lives. In general, which galaxies are seen in the earliest (youngest) stages of their lives?

In the 1960s, Maarten Schmidt determined that quasars were very distant objects by

The black hole mass at the center of a galaxy is generally larger in galaxies with larger central bulges.

We can study how galaxies evolve because ________.

Elliptical galaxies are more likely to be found in clusters than spiral galaxies.

Supermassive Black Holes: A Scientific Theory? Summarize all of the available evidence that active galaxies are powered by supermassive black holes. Do your best to assemble enough evidence that this explanation should be considered a scientific theory in the sense outlined at the end of Section 3.4 (The Nature of Science) of Chapter 3. Do you think astronomers have met this challenge?

Which of the following processes slowed the collapse of protogalactic clouds?

Interactions among galaxies also are thought to influence a galaxy's type in at least some cases. Which of the following does not support the idea that interactions can shape galaxies?

Which of the following is not a good reason why white-dwarf supernovae are good standard candles for distance measurements?

Which of the following features is not a feature of central dominant galaxies?

Recall that a raisin cake is sometimes used to imagine how an expanding universe behaves. Suppose you are in a uniformly expanding raisin cake, sitting on Raisin A, looking at Raisin B, 2 cm away from you. Raisin B is moving away from you at 1 cm/sec. At the same time, you observe another Raisin C, which is moving away from you at 3 cm/sec. How far away is Raisin C from Raisin A?

Why do we believe that starburst galaxies represent a temporary stage in galaxy evolution?

Which of the following phenomena are not thought to be results of collisions or other interactions between galaxies?

Which types of galaxies have a clearly defined spheroidal component?

What does cosmological redshift do to light?