Astronomy Chapter 27

What method would astronomers use to find the distance to a remote quasar?

finding the redshift and sing Hubble's Law

__________ is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other

friction

How are galaxies and quasars related?

quasars are active supermassive black holes at the centers of galaxies

Why do astronomers think that there are fewer quasars today than there were billions of years ago?

quasars are seen when the supermassive black hole at the center of a galaxy has a lot of "food to eat" (stars and gas) and the amount of available food tends to decrease with time

What observation is astronomy, made after the discovery of quasars, was a big help to astronomers in figuring out what quasars really were?

the discovery that the Milky Way Galaxy has a black hole at the center with enough mass fr 4 million SUns

If a nearby galaxy still acts like a quasar today, what is the most likely explanation?

the galaxy must be undergoing a collision with another galaxy that is providing fresh fuel for its central black hole

For galaxies that have super-massive black holes at their centers, how do astronomers find that the mass of the host galaxy and the mass of the black hole are related?

the more massive the galaxy, the more massive the central black hole

How do quasars demonstrate that the universe evolves with time?

the number of quasars reached a maximum some time ago, and now the numbers have been declining

T or F: astronomers use the red-shift an dusing Hubble's Law to find the distance to a remote quasar

true

The bubbles in the galaxy may be evidence that the supermassive black hole at the center of our Galaxy was a quasar a few million years ago

true

After several decades of observation, astronomers have concluded that quasars are...

very powerful and compact sources of energy at the centers of distant galaxies