Exam 13: Galaxies: Normal and Active

Cepheid variable stars are more luminous than the sun.

What assumptions do we make when we use the Hubble constant to estimate the distance to a galaxy?

The radio radiation emitted by a radio lobe is mainly synchrotron radiation.

Elliptical galaxies are primarily made up of massive O and B stars.

Recent high resolution radio observations show that quasars can be classified as

Poor clusters of galaxies often contain an excess of E and S0 galaxies.

Most galaxies appear to be

When discovered in the 1960's, a(n) ____ was found to emit large amounts of energy, but through visual and radio telescopes appeared to be a single point of light much like a star.

What is the primary factor in determining the classification for an elliptical galaxy?

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

An elliptical galaxy could

Quasar redshifts are usually larger than the redshifts of the visible galaxies.

The look-back time is numerically equal to the distance to a galaxy in light-years.

Which of the following is the largest object?

What observational evidence do we have that radio lobes are related to the ejection of gas from galaxies?

What observational evidence do we have that quasars are the centers of very distant galaxies?

The units on the Hubble constant are ____________________.

Some large clusters of galaxies do not appear to contain enough mass to hold themselves together.

The Andromeda spiral galaxy is almost edge-on to us. Astronomers have detected the orbital motion of this and other such galaxies' disk material by

Supermassive black holes are believed to be located at the center of many galaxies because