New Device Reveals Secrets in Neighboring Starburst Galaxy

With the help of a new tool, researchers have uncovered new details of the starburst galaxy M82, including streamers of material escaping the galaxy's disk.

Writing in the Astrophysical Journal, the scientists explain how the new, high-frequency capabilities of the National Science Foundation's Robert C. Byrd Green Telescope (GBT) helped them uncover new traits of the galaxy located 12 million light years away in the constellation Ursa Major.

M82 is a classic starburst galaxy, pumping out stars at a rate up to hundreds of times faster than our own. It's relative closeness made it a prime candidate for the GBT's new W-Band receiver, which the researchers used to detect concentrations of dense molecular gas gathered around regions of intense star production.

This was possible due to the receiver's ability to detect the millimeter wavelength molecular gas emits, making the GBT the largest single-dish, millimeter-wave telescope in the world.

"With this new vision, we were able to look at M82 to explore how the distribution of molecular gas in the galaxy corresponded to areas of intense star formation," said Amanda Kepley, a post-doctoral fellow at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, and lead author on a paper.

According to Kepley, the ability to do so could help scientists discover the reason behind why stars form where they do. Though aware that the presence of dense molecular gas is always paired with star production, neither the relationship between the two nor how the process may differ from one type of galaxy to another is entirely clear. The researchers hope that in the creation of wide-angle maps of the dispersal of gas in galaxies, they might be able to crack the code.

Previous to the W-Band receiver, such observations have been difficult given the feeble shine emitted in millimeter light by those molecules used to map the distribution of dense gas. With the receiver in tow, however, the GBT was able to create the sensitive, wide-angle images of these gases in and around M82.

"The GBT data clearly show billowing concentrations of dense molecular gas huddled around areas that are undergoing bursts of intense star formation," Kepley said. "They also reveal giant outflows of ionized gas fleeing the disk of the galaxy. These outflows are driven by star formation deep within the galaxy."