Galactic and Extragalactic Astrophysics

  1. The Milky Way Galaxy: Our Home
    1. Overall Structure and Components
      1. The Galactic Coordinate System
        1. Longitude and Latitude
          1. Reference Points and Zero Points
            1. Conversion to Other Coordinate Systems
            2. Major Components
              1. Galactic Disk
                1. Thin Disk
                  1. Thick Disk
                    1. Scale Heights and Lengths
                    2. Galactic Bulge
                      1. Classical vs. Pseudo-bulge
                      2. Galactic Halo
                        1. Stellar and Dark Matter Components
                        2. Central Supermassive Black Hole
                          1. Sagittarius A*
                        3. Galactic Parameters
                          1. Mass Distribution
                            1. Rotation Curve
                              1. Escape Velocity
                            2. The Galactic Disk
                              1. Thin Disk and Thick Disk
                                1. Structural Differences
                                  1. Age and Metallicity Gradients
                                    1. Kinematic Properties
                                      1. Formation Scenarios
                                      2. Spiral Arm Structure
                                        1. Density Wave Theory
                                          1. Spiral Pattern Speed
                                            1. Star Formation Triggers
                                              1. Resonance Locations
                                              2. Stochastic Self-Propagating Star Formation
                                                1. Sequential Star Formation
                                                  1. Observational Evidence
                                                  2. Grand Design vs. Flocculent Spirals
                                                  3. Stellar Content and Kinematics
                                                    1. Stellar Orbits
                                                      1. Circular and Eccentric Orbits
                                                        1. Velocity Ellipsoid
                                                        2. Age and Metallicity Distribution
                                                          1. Galactic Chemical Evolution
                                                          2. Stellar Streams
                                                          3. Open Clusters and Stellar Associations
                                                            1. Formation and Dissolution
                                                              1. Tracing Galactic Structure
                                                                1. Age Determination Methods
                                                                2. Warp and Flare
                                                                  1. Observational Evidence
                                                                    1. Physical Mechanisms
                                                                  2. The Galactic Bulge
                                                                    1. Morphology
                                                                      1. Boxy/Peanut Shape
                                                                        1. Observational Signatures
                                                                          1. Formation Scenarios
                                                                          2. Stellar Populations
                                                                            1. Age and Metallicity
                                                                              1. Metallicity Distribution Function
                                                                                1. Age Dating Techniques
                                                                                  1. X-shaped Structure
                                                                                  2. Kinematics and Rotation
                                                                                    1. Bulge Rotation Curve
                                                                                      1. Velocity Dispersion
                                                                                        1. Cylindrical Rotation
                                                                                        2. Microlensing Surveys
                                                                                          1. Stellar Content Probes
                                                                                            1. Exoplanet Detection
                                                                                          2. The Galactic Halo
                                                                                            1. Stellar Halo
                                                                                              1. Field Stars
                                                                                                1. Spatial Distribution
                                                                                                  1. Kinematic Properties
                                                                                                    1. Metallicity Distribution
                                                                                                    2. Globular Clusters
                                                                                                      1. Distribution and Orbits
                                                                                                        1. Age and Metallicity
                                                                                                          1. Multiple Populations
                                                                                                          2. Stellar Streams and Tidal Debris
                                                                                                            1. Origin from Accreted Satellites
                                                                                                              1. Mapping the Halo Structure
                                                                                                                1. Sagittarius Stream
                                                                                                              2. Dark Matter Halo
                                                                                                                1. Evidence from Rotation Curves
                                                                                                                  1. Flat Rotation Curves
                                                                                                                    1. Mass Discrepancy
                                                                                                                    2. Mass Distribution Profile
                                                                                                                      1. Density Profiles
                                                                                                                        1. Total Mass Estimates
                                                                                                                        2. Substructure
                                                                                                                          1. Satellite Galaxies
                                                                                                                            1. Dark Matter Subhalos
                                                                                                                        3. The Interstellar Medium
                                                                                                                          1. Phases of the ISM
                                                                                                                            1. Cold Neutral Medium
                                                                                                                              1. Atomic Hydrogen Regions
                                                                                                                                1. Temperature and Density
                                                                                                                                2. Warm Neutral Medium
                                                                                                                                  1. Transition Regions
                                                                                                                                  2. Warm Ionized Medium
                                                                                                                                    1. HII Regions
                                                                                                                                      1. Diffuse Ionized Gas
                                                                                                                                      2. Hot Ionized Medium
                                                                                                                                        1. Supernova Remnants
                                                                                                                                          1. Galactic Fountain
                                                                                                                                          2. Molecular Clouds
                                                                                                                                            1. Giant Molecular Clouds
                                                                                                                                              1. Star Formation Sites
                                                                                                                                                1. CO Observations
                                                                                                                                              2. Interstellar Dust
                                                                                                                                                1. Extinction and Reddening
                                                                                                                                                  1. Wavelength Dependence
                                                                                                                                                    1. Dust Grain Properties
                                                                                                                                                      1. Extinction Laws
                                                                                                                                                      2. Emission and Scattering
                                                                                                                                                        1. Infrared Emission
                                                                                                                                                          1. Reflection Nebulae
                                                                                                                                                            1. Polarization
                                                                                                                                                          2. Galactic Fountains and Gas Circulation
                                                                                                                                                            1. Supernova-driven Outflows
                                                                                                                                                              1. Gas Accretion and Recycling
                                                                                                                                                                1. Chimney Model
                                                                                                                                                                2. Magnetic Fields
                                                                                                                                                                  1. Observational Tracers
                                                                                                                                                                    1. Field Strength and Structure
                                                                                                                                                                      1. Role in Star Formation
                                                                                                                                                                    2. The Galactic Center
                                                                                                                                                                      1. Sagittarius A*
                                                                                                                                                                        1. Mass Measurement from Stellar Orbits
                                                                                                                                                                          1. Proper Motion Studies
                                                                                                                                                                            1. Keplerian Orbits
                                                                                                                                                                              1. S-star Observations
                                                                                                                                                                              2. Accretion and Flares
                                                                                                                                                                                1. X-ray and Infrared Variability
                                                                                                                                                                                  1. Event Horizon Telescope
                                                                                                                                                                                2. The Nuclear Star Cluster
                                                                                                                                                                                  1. Stellar Content and Density
                                                                                                                                                                                    1. Star Formation History
                                                                                                                                                                                      1. Cusp vs. Core Debate
                                                                                                                                                                                      2. High-Velocity Gas Streams
                                                                                                                                                                                        1. Molecular and Ionized Gas Dynamics
                                                                                                                                                                                          1. Evidence for Inflows and Outflows
                                                                                                                                                                                            1. Fermi Bubbles
                                                                                                                                                                                            2. Nuclear Stellar Disk
                                                                                                                                                                                              1. Young Massive Stars
                                                                                                                                                                                                1. Paradox of Star Formation

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                                                                                                                                                                                            1. Foundational Concepts and Observational Tools

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                                                                                                                                                                                            3. External Galaxies: Islands of Stars