Exploring the Cosmos - Degree Exam 2009 - Galaxies and Large Scale Structure
1. Which of the following comprise the oldest members of the Milky Way?
Type O stars.
Globular clusters.
The Sun and other solar mass stars.
Red giant stars in spiral arms.
2. What makes up the interstellar medium?
O and B stars
Gas and dust
Open clusters
K and M stars
3. How does the interstellar medium obscure our view of most of the galaxy?
It absorbs all wavelengths of light.
It reflects most light from far distances of the galaxy away from our line of sight.
It produces so much visible light that it is opaque and blocks our view of anything beyond it.
It absorbs visible, ultraviolet, and some infrared light.
4. How can we see through the interstellar medium?
By using only the biggest telescopes.
By observing only the brightest visible sources.
By observing at high-energy wavelengths such as X rays and long wavelengths of light such as radio waves.
By using telescopes above the Earth’s atmosphere.
5. Where are heavy elements made?
In stars and supernovae.
In the Big Bang, when the universe first began.
In the interstellar medium.
In none of the above.
6. What can cause a galactic fountain?
A supernova occurring in the halo.
Winds and jets from newly-formed protostars.
The combined effect of spiral density waves.
Multiple supernovae occurring together.
7. Compared with our Sun, most stars in the halo are
old, red, and dim and have fewer heavy elements.
old, red, and dim and have much more heavy element material.
young, blue, and bright and have much more heavy element material.
young, red, and dim and have fewer heavy elements.
8. The disk component of a spiral galaxy includes which of the following parts?
Halo
Spiral arms
Bulge
Globular clusters
9. What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from several collisions among smaller clouds?
The stars in the halo of the Milky Way are organized into several dense clusters arranged throughout the halo.
The Milky Way resembles an elliptical galaxy more than other spirals do.
The bulge of the Milky Way is surrounded by many globular clusters, just as elliptical galaxies are.
Halo stars differ in age and heavy-element content, but these variations do not seem to depend on the stars’ distance from the galactic centre.
10. What two observable properties of a Cepheid variable are directly related to one another?
Its mass and its distance.
The period between its peaks of brightness and its distance.
Its luminosity and its mass.
The period between its peaks of brightness and its luminosity.
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