facebook
twitter
rss
account
search
search
 

Distant galaxy shows remnants of cosmic collision and merger

Feb. 24, 2014 at 6:11 PM   |   Comments

COPENHAGEN, Denmark, Feb. 24 (UPI) -- A stream of stars in a distant galaxy is evidence of an unexpected cosmic collision and merger between two dwarf galaxies, Danish astrophysicists say.

The galaxy Andromeda II is one of a swarm of small satellite galaxies surrounding the Andromeda Galaxy, a spiral galaxy like our Milky Way just 2.3 million light years away.

Movement of some stars in the small galaxy -- less than 1 percent of the Milky Way -- tells us that what we are observing is the remnant of a merger between two dwarf galaxies, scientists at the Niels Bohr Institute at the University of Copenhagen reported Sunday.

Mergers between galaxies of such low mass have not been observed before, they said.

"Stars in a dwarf galaxy often move around at random, but this is not exactly the case for Andromeda II," astrophysicist Nicola C. Amorisco said. "In particular we could see that a stream of stars is moving around differently than the rest in a very coherent way."

The rotating stream of stars in the galaxy is entirely made up of old stars and their properties and movements suggest a dramatic cosmic event, they said.

"What we are seeing is the remains of a collision between two dwarf galaxies, which had a dramatic effect on the dynamics of the remnant," Amorisco said.

Mergers between such small galaxies would have been common in the galaxy formation process in the early universe, but are rare at present times and had not been observed before, the scientists said.

Topics: Niels Bohr
© 2014 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Most Popular
1
SpaceX Dragon returns safely from ISS, splashes into Pacfic Ocean SpaceX Dragon returns safely from ISS, splashes into Pacfic Ocean
2
Google exec breaks skydive record with dive from near-space Google exec breaks skydive record with dive from near-space
3
Powerful new microscope sees cell division in real time Powerful new microscope sees cell division in real time
4
Stone tools reveal Ice Age settlement in the Andes Stone tools reveal Ice Age settlement in the Andes
5
Coal-rich Poland wants concessions in EU climate deal Coal-rich Poland wants concessions in EU climate deal
Trending News
Around the Web
x
Feedback