6. DWARF GALAXIES

6.1 Introduction:Importance of low-L galaxies

• The fundamental observed property of low-L galaxies is low baryon density
  
• The fundamental theoretical explanation is baryonic blowout by winds
  
• Implication: dwarf galaxies have an unusually large dark matter fraction
  

6.2 Observed properties of low-L and low-surface-brightness galaxies

• Fundamental plane parameter correlations
  
• Selection effects: implications for correlations, L function
  
• Icebergs and crouching giants: Malin 1 and relatives
  

6.3 Galaxy Formation.I.Low-Luminosity Galaxies

• Baryonic blowout via galactic winds
  
  • Recall similarity of dwarf S + I and dSph galaxies
    
  • Saito-Dekel-Silk mechanism:blowout of baryons by galactic winds
    
  • Expansion of a stellar system after mass loss
    
  • Observational evidence for mass loss via galactic winds
    
  • Sto hastic starbursts in dwarf galaxies
    
• Ram-pressure stripping
  
  • Evidence for and against
    
• Other processes: revival of dI galaxies by gas accretion
  
• Bombproof evidence that dI galaxies evolve into dSphs:
  
  • The age distribution of stars in dSph galaxies