Assignment 4 - Due 4/2/2002

Put your name on your paper!  Please answer in complete sentences!  Please staple or paper clip your
work together!

 
Read the smaller article first, and answer the following questions:

1. Who first discovered quasars, and when did he/she discover them?

2. Name the three types of Active Galactic Nuclei mentioned in the article.

Now, read the larger article, and answer the following questions:

4. How massive are "super-massive" black holes, measured in solar masses? What's the largest
and smallest black hole mass mentioned in the article?

5. Linda Dressel studied a galaxy named M87 and saw that the gas near the center was moving
fast.  How fast?  How massive of a black hole would be needed to cause speeds this large?

6. Roeland van der Marel studies black holes in galaxies theoretically.  Describe his research so
that your parents could understand it.

7. Meg Urry studies Blazars, another type of galaxy that has black holes in them.  Are they
brighter or fainter than quasars at the same distance?  If they are different, why?

8. Look at the last figure in the article, and summarize what is being shown there.
 

9. Go to the following web site:  http://www.mssl.ucl.ac.uk/www_astro/guides/agn_quasartour.html
Describe the different parts of an active galactic nucleus.  Make a rough drawing of where all of
these parts are located.