Table of Contents

Modern Cosmological Observations and Problems

Chapter 1. Cosmological Model Building

1.1 Overview of Historical Progess in Understanding the Cosmos

1.1.1 Ancestors of our Modern Cosmological Model
1.1.2 The Legacy of the Ancient Greeks
1.1.3 Towards Renaissance Cosmology
1.1.4 Towards the Physical Universe
1.1.5 How Far to the Nearest Star?
1.1.6 General and Special Relativity
1.1.7 Einsteins Biggest Blunder?
1.1.8 The Discovery of Universal Expansion
1.1.9 Models of a Dense Universe
1.1.10 The Discovery of the Cosmic Microwave Background
1.1.11 The Hot Big Bang Model


1.2 Overview of Relevant Cosmological Equations

1.2.1 The Robertson-Walker Metric
1.2.2 The Dynamics of an Expanding Universe


1.30 Modern Cosmological Puzzles

Chapter 2: The Extragalactic Distance Scale

2.1 Overview

2.2 Possible Kinds of Cosmological Models

2.3 Establishing the Extragalactic Distance Scale

2.3.1 The First Rung: Calibrating the Main Sequence Luminosities of Stars via Stellar Parallax

2.3.2 The Second Rung: Distances to stellar clusters

• Main Sequence Fitting
• Convergent Point Method
• Hyades and Pleiades Clusters

2.3.3 The Third Rung: Determining the Zeropoints of Standard Candles

• The Cepheid Variable Period- Luminosity Relation
• Possible Problems with Cepheids
• RR Lyrae Absolute Magnitude Scale
• The Baade-Wesselink Technique
• Brightest Red Supergiants

2.3.4 Distances to Local Group Galaxies

• The Large Magellanic Cloud
• The Andromeda Galaxy - M31
• The Other Spiral - M33

2.3.5 Extragalactic Distance Indicators

• The Tully-Fisher relation
• The Luminosity Function of Planetary Nebulae
• Surface Brightness/Luminosity Fluctuations
• The Luminosity of Supernovae
• The Globular Cluster Luminosity Function

2.3.6 The Distance to the Virgo Cluster

2.3.7 Correction for Bias in Extragalactic Samples

2.3.8 Hubble Space Telescope Distance Estimates to Virgo

2.3.9 Summary of Virgo Distance Estimates

2.3.10 Direct Astrophysical Distance Measurements

• The Sunyaev-Zeldovich (SZ) effect
• Gravitational Lensing
• Superluminal Motion in Radio Sources
• Virial Masses

Chapter 3: Structure in the Universe: Galaxies, Clusters, Superclusters, Walls and Voids

3.1 Overview and Caveats
• The Saches-Wolfe Effect
• Biased Tracer Populations

3.2 Hierarchical Structures Uncovered

3.2.1 Groups of Galaxies
3.2.2 Clusters of Galaxies

• Evidence that Clusters of Galaxies are Gravitationally Bound
• Cluster Timescales

3.2.3 Clusters of clusters: Superclusters

3.4 There's More Out There Than Just Light

3.5 Redshift Surveys: Defining Physical Structures

3.5.1 Hierarchical Clustering Patterns
3.5.2 The Coming of the Stickman
3.5.3 The Void in Bootes
3.5.4 The Deeply Probed Universe
3.5.5 Correlation Scales


3.6 The Peculiar Velocity Field

3.6.1 Inflows and Outflows
3.6.2 Virgocentric Flow
3.6.3 Large Scale Flows: Continental Drift in the Nearby Universe?
3.6.4 Infall Around the Great Attractor: A Case Study


3.7 The Physical Structure of Voids and Walls: A Case Study

3.7.1 Are Voids Real Structures?
3.7.2 Are Walls Really Thin?


3.8 A Really, Really Big Flow?

3.9 A Determination of H_o Using the Virgo and Coma Clusters

Chapter 4: Dark Matter in the Universe

4.1 Overview
4.1.1 The Virial Theorem

4.2 Evidence for Dark Matter as a Function of Scale Size

4.2.1 The Solar System
4.2.2 The Solar Neighborhood
4.2.3 Galactic Scales


• Mass distributions and predicted rotation curves
• Observational Evidence for Flat Rotation Curves

4.3 Other Dark Matter Indicators for Galaxies

4.3.1 Hot Halos Around Elliptical Galaxies
4.3.2 Binary Galaxies
4.3.3 Stellar Population Effects on Mass-to-Light Ratios
4.3.4 Some Measured Values for M/L
4.3.5 Clusters of Galaxies

• Substructure and the Illusion of Large M/L

4.4 The Large Scale Distribution of Dark Matter

4.5 The Inflationary Paradigm and OMEGA = 1

4.6 Dark Matter Candidates and Detection

4.6.1 Normal Baryonic Dark Matter
4.6.2 Exotic Baryonic Dark Matter
4.6.3 Nucleosynthesis Constraints on Baryonic Matter
4.6.4 Non-baryonic Dark Matter 4.6.5 Direct Detection of Dark Matter
4.6.6 The Microlensing Surveys
4.6.7 The Solar Neutrino Experiment


4.7 Further Implications of Dark Matter

4.8 Summary

Chapter 5: Structure Formation Scenarios and Observational Constraints

5.1 The Gravitational Instability Paradigm
5.1.1 Continuity Equation
5.1.2 Euler's Equation
5.1.3 Stability Criterion in a Static Fluid
5.1.4 Gravitational Instability in an Expanding Universe
5.1.5 The OMEGA = 1 Solution
5.1.6 The OMEGA = 0 Solution
5.1.7 Numerical Games with the Jeans Mass


5.2 Statistical Characterization of Structure

5.2.1 What Comes First - Galaxy-size or Cluster-size Potentials?


• The Top-down Scenario
• The Bottom-up Scenario
• The Baryon Dominated Scenario

5.2.2 Biasing in the Universe

5.3 Some Possible Cosmogenic Scenarios
5.3.1 The Power Spectrum of the Galaxy Distribution
5.3.2 Can CDM be Saved?
5.3.3 Beyond CDM: More Exotic Scenarios
• Primordial Baryon Isocurvature
• Toplogical Defects
• Explosions
• Primordial Turbulence

5.4 Observational Constraints
5.4.1 Large Scale Constraints
• COBE
• H_o
• The Observed Power Spectrum
• Clusters of Galaxies
• QSO absorption lines
• Gravitational Lensing

5.4.2 Small Scale Constraints

• Dwarf Galaxies and Massive Halos
• High Redshift Galaxies
• The Epoch of Galaxy Formation
• Pairwise and Peculiar Velocities

5.5 Summary

Chapter 6: The Distribution of Baryons in the Universe

6.1 Extragalactic Backgrounds
6.1.1 The Radio Background
6.1.2 The Infrared Background
6.1.3 The UV Background
6.1.4 The X-ray Background
6.1.5 The Gamma Ray Background

• The Mystery of Gamma Ray Bursters

6.1.6 A Possible Decaying Particle Background

6.2 The Space Density of Galaxies

6.2.1 The Luminosity Function of Galaxies
6.2.2 Deep Galaxy Counts: The Mystery of the Faint Blue Galaxies
6.2.3 A New Population of Galaxies at z =0


6.3 Surface Brightness Selection Effects

6.3.1 Diameter Limited catalogs
6.3.2 Flux Limited Catalogs


6.4 Discovering Low Surface Brightness Galaxies

6.4.1 The Space Density of Galaxies as a Function of surface brightness
6.4.2 The Properties of LSB Galaxies
6.5.3 Cosmological Relevance of LSB Galaxies

6.5 Summary

Chapter 7: Concluding Remarks and Future Prospects

7.1 Revisting the Questions of Chapter 1
• What is the age of the universe as determined from the observed expansion rate and cosmological distance scale?
  
• Is there a need to invoke the cosmological constant to reconcile the ages of the oldest stars with the value of the Hubble constant?
• What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution?
• What is the evidence for the existence of dark matter and what is its overall contribution to the total mass density of the Universe?
• How did structure form in the Universe and what formation scenarios are consistent with the current observational data?
• Where do the baryons reside? Are they predominately inside or outside of galaxies? How efficient was the process of galaxy formation? What is the true nature of the galaxy population? Do we have a representative survey of galaxies in the nearby universe from which coherent arguments about galaxy formation and evolution can be made?

7.2 Significant Observations as a Function of Redshift

7.3 Future Observations

• The Sloan Digital Sky Survey
• CMB anisotropy measurements on the 0.5 -- 1.0 degree scale
• Keck 10-meter
• The Hubble Deep field
• Surveys for weak gravitational lensing
• Particle Physics and Cosmology
• The Advanced X-ray Astronomical Facility (AXAF)
• Shuttle Infrared Telescope Facility (SIRTF)