Astr/Phys 328/428 Midterm Exam Questions (2010 edition)
There will be three questions taken
from this list. You should plan on spending ~ 2-3 bluebook pages
answering each one. Any sketches you draw should have labeled axes,
with at least relative scales. Any numbers you give should be "ballpark
correct." Any equation you use must have terms described.
- Why do we need to study relatively distant
galaxies to get a get a measure of the Hubble constant? Why can't we
just use distances to nearby galaxies, where Cepheids give us good
distances, to measure H0?
- Describe several reasons (both physical and
observational) why high redshift
galaxies might look different from galaxies in the local universe.
- Describe the "surface brightness fluctuation"
technique for finding distances to galaxies. Is this technique better
for spirals or ellipticals? Why?
- Write down the Friedmann equation, and describe
each term. Using the Friedmann equation, derive expressions for the
for an Omega=1, Lambda=0 universe:
Explain the supernova
project, the cosmological test it is making,
and the recent results from this project.
- the current age of the Universe
Describe what we mean by "peaks" in the power
the microwave background. What causes these peaks, and what do they
us about the Universe?
Describe the Sunyaev-Zeldovich Effect, and how we
can use it to constrain cosmological parameters. What data is needed
for this test?
Describe the process of Big Bang Nucleosynthesis
and how it can constrain the baryon fraction of the universe. What
value for OmegaB is indicated by BBN?
Describe the Tully-Fisher relationship (including
its physical implications). Discuss the data you need to measure H0
with Tully-Fisher, and explain how the cluster incompleteness bias can
influence your answer.
Describe the five foundations of modern
Explain what a K-correction is and what it
depends on. Explain qualitatively how a K-correction for an elliptical
galaxy would be
different from a K-correction for an actively star-forming spiral
Why is the surface brightness of a galaxy
independent of distance in the nearby universe, but a strongly
decreasing function of redshift at cosmological distances?