Astr/Phys 328/428 Final Exam Study Questions (2006 edition)
The
final exam is Wednesday, December 20th,
12:30-3:30.
It will consist of five questions
taken from this list. You should plan on spending ~ 2-3 blue book pages
answering each one. Remember to always answer with a "what" (i.e.,
describe the object/effect/concept in question) and a "why" (i.e.
explain physically why it behaves the way it does).
Definitions
- "several" = "three or more"
- "sketch" = "a plot with labeled axes"
- 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 and sketch the Press-Schecter
relationship for collapsed dark matter halos. Why does it have the
shape it does? How and why does Press-Schecter evolve with redshift?
- Explain what the Sunyayev-Zeldovich effect is
and how it used
to measure
the Hubble constant.
- Describe Big Bang Nucleosynthesis (BBN).
Observationally, how can we constrain OmegaB from BBN
arguments?
- Explain the test behind the supernova cosmology
project,
and the recent results from this project. One systematic effect that
people have had is what would happen if the universe was filled with
dust. How would a "dusty universe" affect the test, and how might you
check for this effect?
- Describe the physics behind the microwave
background, and explain how the CMB constrains models for structure
formation in the universe.
- Why is "standard CDM" cosmology (i.e., OmegaM=1,
OmegaL=0)
dead?
Give me several well described arguments.
- How and why does structure form differently under
hot dark
matter and cold dark matter models?
- Observations suggest that OmegaM ~
0.3. Why
couldn't the dark matter be all baryonic? Give
several reasons why.
- Explain the Lyman break technique and how we
use it
to identify
high redshift galaxies. Describe the properties of Lyman Break Galaxies.
- Explain how we can use the properties of
elliptical galaxies to constrain their age of formation. What
constraints do we get on their formation redshift from these arguments?
- Describe qualitatively how structure grows with
time in the
following sets of universes:
- OmegaL = 0, OmegaM
increasing from
0.1 - 1.0
- OmegaM = 0.3, OmegaL
increasing from
0.0 - 0.7
Make sure you explain why
structure
evolves
differently in these different universes. Based on these arguments
(only), and
the observed structure in the universe what value or ranges of values
are
acceptable for OmegaL and OmegaM? - Describe how we can use peculiar velocities to
measure the
matter content of the Universe? How do we derive those peculiar
velocities?
In this context, what is the Great Attractor?
- Describe the five foundations of modern cosmology.
- Why do we currently believe that the
cosmological
constant
(or "dark energy" in general) is real? Give several lines of evidence.
- Describe how globular clusters are age dated, and
how these ages can be used to
constrain cosmological parameters (ie OmegaM, OmegaL,
H0). Be specific!
- Describe several reasons why high
redshift galaxies might look different from galaxies in the nearby
universe (think both about observational effects and the galaxies
themselves...).
- Describe what Damped Lyman Alpha systems are and
how they can help us constrain the star forming history of the Universe.
- Describe several lines of evidence suggesting
that "normal" galaxies (spirals and ellipticals) were largely formed
and in place by z=1.
- Write down the Friedmann equation and describe
each term. Using the Friedmann equation, derive the following for an
OmegaM=1, OmegaL=0 universe:
- R(t)
- t(z)
- the current age of the universe