Exam 16: A Universe of Galaxies

A galaxy with a total mass of 10⁶ M_Sun is most likely to be:

What fraction of galaxies have black holes at their centers?

What property of a Type Ia supernova must be measured in order to use it as a standard candle?

Why was the large size of Edwin Hubble's telescope essential for resolving the nature of spiral nebulae?

Which galactic phenomenon is triggered by the same process as spiral structure?

Contrast spiral and elliptical galaxies in terms of their color,gas content,and orbital properties.

Galaxy A is located at the North Celestial Pole,while galaxy B is located at the South Celestial Pole.Galaxy A is 100 Mpc from Earth,while galaxy B is 500 Mpc from Earth.What is the relative velocity between them,as observed from Earth?

What was the subject of the "Great Debate" in astronomy?

An extragalactic source with a compact size and strong,broad emission lines is also likely to have:

An astronomer measures the rotation speed of a spiral galaxy.How can she use this to estimate the galaxy's distance?

Edwin Hubble believed that:

In a barred spiral galaxy,the spiral:

The mass of a supermassive black hole within the galaxy will most accurately predict the:

As a result of collisions,galaxies are most likely to evolve from:

Which of the following accurately characterizes emission lines from active galactic nuclei?

An astronomer discovers a bright,steady source of high-energy gamma rays at the center of a galaxy.What is the most likely explanation for this source?

A galaxy is flanked by a pair of regions of bright radio emission,each 300 kpc across.What is the most likely power source of this emission?

Astronomers discover a galaxy 1.4 Gpc from Earth.What is its velocity relative to Earth,and in which direction does it point?

Which cosmic distance measurement techniques rely on the observation of standard candles?

An astronomer discovers an extremely luminous galaxy with broad emission lines that have very large redshifts.This is most likely a: