The Mice at Play

Joshua E. Barnes & John E. Hibbard

Embargoed until April 30, 1:00 pm EDT

Institute for Astronomy press release on the computer simulation of The Mice is available at   <>  .

Space Telescope Science Institute press release on the Advanced Camera for Surveys is available at   <>  .

More details on models of interacting galaxies are available at   <>  .

More observations of The Mice are available at   <>  .

Advanced Camera for Surveys image of The Mice. For more images, see the Space Telescope ACS press release.

Computer simulation of The Mice: Animation (2.4 Mbyte mpeg) or Selected Frames. For more animations, see Models of Interacting Galaxies.

Morphing The Mice (3.4 Mbyte mpeg). In this version, the computer simulation morphs into the real image and back.

Another rendition of the same simulation (6.6 Mbyte mpeg). This animation shows a somewhat larger field of view. In addition, the dark halos of the galaxies, accounting for 80% of the mass, are shown in red.

Image of The Mice, taken with the University of Hawaii 2.2 meter telescope on Mauna Kea. Although not nearly as detailed as the ACS image, this picture shows the full extent of the tidal `tails'. For more images, see John Hibbard's web page on NGC 4676.

Very Large Array observations and computer simulation. Besides matching the appearance of The Mice, a good simulation should also reproduce the motions of both galaxies and their tails. Here, red contour lines show velocities of interstellar hydrogen gas in The Mice measured using the VLA, and blue dots show the velocities predicted by the computer. The agreement is quite good.

For more observations, see John Hibbard's web page on NGC 4676.

Joshua E. Barnes (

Last modified: April 30, 2002