Reference no: EM133199199
1. Describe the differences between the main regions of the galaxy by describing the following characteristics of the listed areas: the age of stars in the region, the amount of gas and dust in the region, the amount of star formation in the region, and the orientation of orbits in the region.
a) the galactic halo
b) the galactic bulge
c) the galactic disk
2. Identify one particular type of celestial object that is unique to each of the following regions of the galaxy, and give a brief description of the object.
a) the galactic halo
b) the core of the galactic bulge
c) the galactic disk.
3. Explain how variable stars allow us to measure very long distances.
4. Explain briefly why spiral arms are places of active star formation.
5. Why is it much easier to study the center of the galaxy with radio waves than with visible light?
6. Briefly describe how our galaxy formed. How does this model explain two differences between disk and halo stars?
7. Describe two observed features of the galactic core that lead astronomers to believe that there is a supermassive black hole in the center of our galaxy.
8. Briefly explain how observations lead astronomers to conclude that the Milky Way galaxy is embedded in a volume filled with "dark matter"
9. Describe at least four differences between elliptical and spiral galaxies.
10. In general terms, what does Hubble's Law say? What does it imply about the structure of the Universe?
11. What is the "Hubble Sequence"? Hubble interpreted the diagram to mean something that was later shown to be false: what was it?
12. List at least four characteristics that active galaxies exhibit.
13. How are Seyfert galaxies similar to our own Milky Way? List some ways that they are different.
14. Describe the unusual feature of a radio galaxy. Why do we see two different types of radio galaxies?
15. Why do the spectra of quasars lead us to believe that they are the brightest known objects in the universe?
16. How are the features of active galaxies explained? Refer specifically to at least three characteristics from the previous question