Unusual gas ripples offer signs of a dwarf galaxy speeding away
Sukanya Chakrabarti/Rochester Institute of Technology
The study of disturbances in a galaxy’s structure (essentially, galaxy quakes) to discover dark, but massive, cosmic objects.
KISSIMMEE, Fla. — Ripples in the Milky Way’s outer layers of gas were the first clue. Now, scientists suspect they have found a small, faint galaxy that brushed past our galaxy a few hundred million years ago. This dwarf galaxy doesn’t have many stars, but it is rich in dark matter, the invisible but predominant source of mass in the universe. Sukanya Chakrabarti, an astronomer at the Rochester Institute of Technology in New York, reported the findings January 8 at a meeting of the American Astronomical Society.