Close to Home: The Milky Way Galaxy

 
The Milky Way has its own set of satellite galaxies, the largest of which is the Large Magellenic Cloud.

The Milky Way also has a modest bar, and a thick disk component. But the thick disk represents only ~ 15% of the total disk mass (Majewski 1993),  suggesting that no significant accretion events have happened recently.


 
In 1994, the Sagittarius dwarf was discovered, on the opposite side of the galactic center (Ibata etal 1994).
 
  • d=25 kpc

  •  
  • M ~ few x 107 Msun

  •  
  • elongated 34o in extent 

  • (Mateo etal 1996)

Other evidence for halo substructure is mounting:


 
 
And in the future, there's always Andromeda....
 
  • d=750 pc

  •  
  • vr=-200 km/s

  •  
  • t = several Gyr?