Review Questions

1. What is a Lyman-break galaxy (LBG)? How are they found in searches (what techniques and/or spectral features or colors are used to select them)? What type of galaxy is an LBG (what are their general properties)?

2. What is a Ly⍺ emitter (LAE)? How are they found in searches (what techniques and/or spectral features or colors are used to select them)? What type of galaxy is a LAE (what are their general properties)?

3.  There are three main approaches (types of surveys) for building samples of galaxy-absorber pairs. Describe how each type of survey is carried out and elaborate on the pros and cons of each in terms of controlling sample bias and possibly skewing scientific results. 

4. If we do an experiment and examine equivalent width as a function of impact parameter, what are we exploring about the CGM?  Often, we normalize the impact parameter by the virial radius of the host galaxy and examine equivalent width as a function of this normalized projected separation. When doing so, what are we taking into account in our experiment and why would we take this into account?

5. What is the covering fraction (not overing factor!) and how is it measured? How is a covering fraction different from a covering factor?  When defining the covering fraction, why is it important to apply a minimum equivalent width or minimum column density threshold?

6. What is galaxy inclination and how is it defined?  What is the galaxy-quasar sightline azimuthal angle and how is it defined?

7.  Accounting for galaxy orientation relative to the quasar sightline can provide insight into the spatial-kinematics distribution of absorbing gas around galaxies.  (i) In terms of galaxy inclination and galaxy-quasar sightline azimuthal angle, what are the four general categories of "galaxy orientation"? (ii) Briefly describe the prominent spatial kinematics that can be investigated for each?

8. Why do we say that galaxy-absorber studies are a "dull knife" as an experimental technique for observationally investigating the details of the baryon cycle in the CGM.

Problems

1. Under construction