Exam 16: Normal and Active Galaxies: Building Blocks of the Universe

The flattest of all galaxies belong to class

For finding the distance to M31, Hubble relied upon

The Local Group of galaxies spans about 30 million light-years in diameter.

Contrast the sizes and membership of the Local Group and Virgo Cluster.

In going from Sa to Sc, the size of the reduces significantly.

A possible evolutionary sequence is quasar to to normal spiral galaxy.

The Tully- Fisher relation allows us to determine the distance to the most distant galaxies.

The most tightly wound spiral arms belong to Hubble's type Sa.

According to Hubble's Law, the larger a galaxy's redshift, the greater its .

Centaurus A, with two large radio lobes, is an active galaxy.

As the name quasi- stellar radio sources implies, all quasars are strong radio sources.

Intermediate between E7 and Sa galaxies, _ have a disk but no gas or dust.

Radio galaxies emit only radio waves, and are not otherwise observable.

The Milky Way is considered to be an intermediately wound, barred spiral, which would be type , according to Hubble.

The Tully- Fisher relation exists between the galaxy's luminosity and its

Seyferts have properties that lie between quasars and normal spiral galaxies.

In this diagram, the galaxy at the left side is a(n)

Although theory says a massive black hole with an accretion disk should be emitting X- rays, many black holes emit

While our Magellanic Clouds are irregulars, the companions to Andromeda are ellipticals.

The additional energy given off by active galaxies is because of their higher stellar density.