Given this very close arrangement, astronomers are
intrigued by the galaxies» apparent lack of any significant gravitational interaction; only a faint bridge of neutral hydrogen gas — not visible in this image — appears to stretch between them.
A Giant Galactic Ghost
Intrigued by faint blurs on old photographic plates of the Virgo
galaxy cluster, a nearby region teeming with
galaxies, Oregon's Bothun and colleagues wondered if the apparitions might be smallish
galaxies with «low surface brightness» — astronomer - speak for emitting less light per unit area than typical
galaxies.