Changing Gears: The Big Picture

Our Milky Way Galaxy

Our Place in the Milky Way

• The naked eye Milky Way:
  southern hemisphere, zoom to dark lanes, more bands
• Galileo: telescope
• Immanuel Kant
• William Hershel's model (top view)
• Harlow Shapley globular cluster distribution: on the sky, in space
• interstellar dust: microscopic view, in a dark cloud and reflection nebula
  another example of scattering and absorption
• simulated view of Milky Way seen from outside; a possible similar galaxy

Multiwavelength Milky Way: All-Sky Views

• optical: dust-obscured
• near infrared: stars, less dust
• radio at 21 cm: neutral hydrogen atoms
• Galactic coordinates, with constellation

Galactic Rotation Curve

• warmup: solar system rotation curves here, here, and here
• Milky Way rotation curve: data
• Milky Way rotation curve: interpretations

Milky Way Dark Matter

• What the heck is it?!?
• what it is not
• favorite candidate today: exotic relic particles
  underground detection experiment