From Wired, by Lisa Grossman
This gorgeous new X-ray image of the nearby galaxy M82 shows a frantic burst of star formation that may have been triggered by a close encounter with a nearby galaxy.
M82 is “the prototypical starburst galaxy in the nearby universe,” said astronomer Roy Kilgard of Wesleyan University, who presented the new image in a press conference Thursday at the meeting of the American Astronomical Society. The galaxy lies just 12 million light-years from the Milky Way, and is the brightest galaxy in the sky in infrared wavelengths.
The image above was captured by the Chandra X-Ray Observatory over the course of nearly two years.
“It’s extraordinary. I’ve never seen detail like this in an X-ray image before,” Kilgard said.
More than 100 point-like X-ray sources show up in Chandra’s view of the galaxy, eight of which may be black holes stealing gas and other matter from companion stars much more massive than the sun.
NASA’s WISE (Wide-Field Infrared Survey Explorer) also observed M82 (the golden galaxy at the top of the image below) before the telescope ran out of coolant in October 2010. WISE’s infrared view covers an area 11 times the area of the full moon, and also captures M82’s galactic neighborhood.
The blue grand-spiral galaxy M81 dominates the bottom center of the image, and the small elliptical galaxy NGC 3077 lies to the bottom left. The faint green streaks that crisscross the image are lanes of dust in the Milky Way.
The huge burst of star-forming activity in M82 was probably triggered by a recent near-miss collision with M81, said astronomer Ned Wright of the University of California, Los Angeles. The encounter stopped M82’s rotation, and dumped a huge amount of gas into the galaxy’s center, where it collapsed into bright, young stars.
Near-miss collisions often result in distorted, wonky-looking galaxies. But for M81, the flyby with M82 may have enhanced its spiral structure.
“Eventually these things will merge into some giant mega-galaxy,” Wright said.
The data from the two space telescopes is “quite complimentary,” Kilgard said. Combining the X-ray and infrared views of M82 can help astronomers determine how star formation is related to the birth of black holes with stellar companions
Images: 1) NASA/CXC/Wesleyan/R.Kilgard et al. 2) NASA/JPL-Caltech/UCLA