Models of Merging Galaxies
Chris Mihos, Department of Astronomy, Case Western Reserve University
Images and animations on this page are © 1994-1999 Chris
Mihos. You may download them for your own personal use, but please do not
reproduce in published form (ie in print or web publications) without prior
consent. Thank you.
New movies here
Ring galaxy simulation
This is a big MPEG file -- 9 megabytes. Ask yourself again if you want
to download something that big. If you are sure, here
Online lecture given at the 1998 Meeting of the American Association for
the Advancement of Science
Here are quick links to the embedded animations:
Equal Mass Merger of Two Disk Galaxies
This image shows a merger between two disk galaxies
of equal mass. The galaxies approach, collide, and draw apart; energy transfer
during the encounter slows their motions so that they reapproach, collide,
and merge. The image is color-coded to show the rate of star formation
(blue = quiescent, red = more active, white = most active) rather than
the actual brightness of the galaxies due to stars. You also may download
a MPEG movie (485 KB) of this simulation.
A Prograde-Retrograde Merger
This MPEG movie (621 KB) shows part of the evolution
of two colliding disk galaxies -- one rotating in the direction of the
encounter orbit, and the other rotating against the encounter. The galaxies
are affected differently as a result of the combination of rotation and
tidal effects. The blue particles in the movie represent stars in the galactic
disks and are collisionless, while yellow represents gas, which can collide,
shock, and dissipate energy. The effects of star formation are not shown
in this movie.
More Images of Equal Mass Mergers
Satellite Galaxy Mergers
This image shows a merger between a large disk
galaxy and a low-mass dwarf companion. Again, the image shows the star
formation rate in the disk galaxy, color-coded as for the previous encounter.
The dwarf companion contains no gas; because of this it does not form stars
and so is invisible in this image. The companion's center of mass is indicated
by the white circle. There also is an accompanying MPEG
movie (1.1 MB) of this encounter.
More Images of Satellite Mergers
You also may read a more detailed description
of these models and a technical description
of the modeling techniques.
The models shown here were done largely on the Cray C90 at the San
Diego Supercomputer Center.
Department of Astronomy
Case Western Reserve University
10900 Euclid Ave
Cleveland, OH 44106