Galaxies

• Types:
  
  • Spiral: ongoing star formation
  • Barred spiral
  • Elliptical
  • Irregular: Sextans A, LMC, SMC
  • interactions and consequences: collisions/mergers, starbursts
  • dynamics: rotation curves. M33, M31 optical and rotation curve, other examples
  • Galaxy clusters: Virgo, Coma, Perseus
    cluster gravitational lensing here and here
  • testing dark matter: the bullet cluster

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  Changing Gears: The Big Picture

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  Cosmology

  Where are the Galaxies: Structure of the Universe

  • cosmological principle: homogeneous & isotropic
  • actual data: 2dF Galaxy Redshift Survey
    • survey geometry
    • results in 3-D

  Galaxy Motion Relative to Us

  • Hubble's law: orignal paper, modern update
  • Hubble motion: artist's conception

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  OBAFGKM(LT) Contest: Winners