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

What is the nearest huge cluster of thousands of galaxies, to which the Local Group may belong?

Relate Seyferts to spirals.

The optical classification of galaxies was pioneered in the 1930s by .

In the Hubble Classification scheme, the three main types of galaxies are , , and .

The most luminous objects known in the universe are

Discuss the population, size, and types of galaxies we find in our Local Group.

Why do quasars die out over time?

Why do some radio galaxies appear to have lobes while some do not?

The supermassive black holes that may be powering active galaxies emit only synchrotron radiation.

Elliptical galaxies contain only Population _ stars and little gas and dust.

The largest nearby cluster of galaxies lies about 17 Mpc distant in

Why do rich clusters of galaxies contain a larger fraction of ellipticals than normal?

In the Local Group, most members are either dwarf ellipticals or spirals.

A galaxy with a blueshift is moving Earth.

The black hole in the core of a Seyfert galaxy consumes the equivalent of hundreds of solar masses a day.

The flattest of all the ellipticals are class .

Most of the galaxies in the Local Group are

Active galaxies emit most of their radiation as visible light.

The combined of the Local Group binds them together.

Fast- moving electrons, moving close to c, in a strong magnetic field generate radiation.