15-05 Galaxy Collisions

  • The Antennae (NGC 4038, 4039) and the Mice (NGC 4676)


    [Tidal force distorts galaxies and induces star formation.]
     
  • Passing by... the case of M51


    [Colissions may produce spiral arms.]
     
  • Galaxies collide much more often than stars.




    [The M81 group, 1 degree across, 3.5 Mpc away. Left: Palomar Sky Survey. Right: VLA HI measurement.]
     
  • Our Milky Way is eating a dwarf elliptical, may have hydrogen gas links with LMC and SMC, and will collide with M31 in about 3.8 Gyrs...

    [Computer simulation of the collision between M31 and the Milky Way. The time tag is 0, 2, 3.75, 3.85, 3.9, 4, 5.1, and 7 billion years from top left to bottom right. (Credit: NASA, ESA)]