Galactic harassment
Stories from Physics
for 11-14
14-16
In 1998, astrophysicists observed the effects of ‘galactic harassment’ - the effect of multiple, close, high-speed encounters between massive galactic clusters. The Hubble Space Telescope is sensitive enough to detect the diffuse light from stars that exist between galaxies, known as extragalactic stars, and the researchers identified a group of red giant stars that had been ripped from their galaxies.
References
Galactic harassment
H. C. Ferguson, N. R. Tanvir, & T. von Hippel, Detection of intergalactic red-giant-branch stars in the Virgo cluster. Nature, vol. 391, 6666, 1998, pp. 461-463.