Homework 10, the last one...

Please answer at least 4 of the following 5 questions correctly for full credit:

Question 1

By spectral classification: What kind of stars are found in the galactic halo? O and B stars or K and M stars?

Question 2

Which spectral classes of stars give a spiral's galactic disk its bluish hue?

Question 3

Which two hydrogen lines are used to map the matter distribution in the galactic disk?

Question 4

What do we think is making the spiral arms in a spiral galaxy and why can the orbits of the stars in the disk of a spiral not be responsible for the beautiful spiral arms?

Question 5 (the conceptual one)

How do we know how much dark matter is hidden inside a galaxy?
Please submit your answer as plain test in the main message body of an e-mail to kai-1060-hw@physics.utah.edu before midnight (MST) on April 17, 2008. Plain text in the main message body of your e-mail means no attachments!!!
Last modified: Fri Apr 11 13:15:11 MDT 2008