Exam 14: Investigating Other Galaxies

The observational fact about a Cepheid variable star that leads to a measurement of its distance from Earth is that its period of variation is directly related to its

What is the Tully-Fisher relation?

What percentage of the mass required by the cluster's observed gravity,as shown by the speeds of galaxies in the cluster,is represented by the mass of the presently observable matter in a typical rich cluster of galaxies?

Which of the following fundamental astronomical questions did Curtis and Shapley debate in 1920 in their famous confrontation?

The Tully-Fisher relation is mainly used for determining the temperature of a galaxy.

In order for gravitational lensing of a distant quasar to occur,the galaxy producing the lensing must

The rotation curve of a galaxy is a graph showing the galaxy's speed of rotation at different distances from the center.The observed rotation curve in the outer parts of a typical large spiral galaxy

A preponderance of evidence suggests that an active galaxy consists of a

What are the characteristics of quasars?

No known galaxy has its spectra lines shifted toward the blue part of the spectra.

Lenticular galaxies are intermediate between spiral and elliptical galaxies.

A rich cluster contains hundreds or even thousands of galaxies,whereas a poor cluster,often called a group,may contain a few dozen.

Distances to a nearby galaxy can be determined most accurately by

Gravitational lensing involves using a special type of lens in a telescope to view gravitational waves.

Various techniques to determine distance to objects in the universe are collectively known as the

An elliptical galaxy has a lot of hot,young,blue stars in its core.

According to the Hubble classification scheme,an Sa galaxy has a(n)

Which of the following is NOT considered a standard candle?

A starburst galaxy appears to be a galaxy in which

The Hubble classification for a very flat elliptical galaxy is