A galactic ‘hit and run’ collision caused a period of intense star formation in the galaxy NGC 4485 a new image from NASA shows.
The irregular galaxy NGC 4485– located in the constellation of Canes Venatici 25 million light-years away–shows telltale signs of having been involved in a galactic ‘hit-and-run’ accident with a bypassing galaxy. But, rather than destroying the galaxy, the chance encounter is spawning a new generation of stars, and presumably planets.
This new image, captured by Hubble’s Wide Field Camera 3 (WFC3), provides further insight into the complexities of galaxy evolution.
The right side of the galaxy is ablaze with star formation, shown in the plethora of young blue stars and star-incubating pinkish nebulas. Whilst the left side appears intact– containing hints of the galaxy’s a spiral structure and normal galactic evolution before the collision.
The larger culprit galaxy, NGC 4490, is off the bottom of the frame of the main image above. The two galaxies sideswiped each other millions of years ago and are now 24 thousand light-years apart. The gravitational tug-of-war between the two galaxies created rippling patches of higher-density gas and dust within both.
This activity triggered a flurry of star formation.
This galaxy is a nearby example of the kind of cosmic bumper-car activity that was more common billions of years ago when the universe was smaller and galaxies were closer together.
Main image caption: An image of irregular galaxy NGC 4485, captured by Hubble’s Wide Field Camera 3 (WFC3). (NASA, ESA; acknowledgement: T. Roberts (Durham University, UK), D. Calzetti (University of Massachusetts) and the LEGUS Team, R. Tully (University of Hawaii) and R. Chandar (University of Toledo))