Starburst galaxy could shine light on stellar birth
Never-before-seen details of starburst galaxy M82 could point the way to understanding more about how stars form.
Streamers of material along with concentrations of molecular clouds surrounding pockets of intense star formation in the starburst galaxy, M82, have been observed for the very first time thanks to the high-frequency capabilities of the National Science Foundation’s Robert C. Byrd Green Bank Telescope in West Virginia.
Found in the constellation Ursa Major and around 12 million light years away, M82 earns its place in the starburst category; it’s continually making stars at an incredibly productive rate, churning out newborns at a whopping tens- to hundreds-of-times faster than our own Milky Way.
“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,” lead scientist Amanda Kepley of the National Radio Astronomy Observatory (NRAO) at Green Bank, West Virginia, says. “Having this new capability may help us understand why stars form where they do.”
Since the M82 is so close, it’s an ideal target for the Green Bank Telescope’s newly fitted receiver that is capable of probing into the regions that throw out light in millimetre wavelengths – in particular, molecular gas; one of the important ingredients in making stars.
Star formation is recognised to happen in dense molecular clouds. However with their birth being a poorly understood area, astronomers have been struggling to find a link between these clouds and how they come about. They hope that with the advent of wide-angle maps of the gas found in galaxies – just like those of M82 – they can gain a clearer picture of what’s really happening.
“The GBT data clearly show billowing concentrations of dense molecular gas huddled around areas that are undergoing bursts of intense star formation,” explains Kepley. “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.”
The rise of higher resolution observations made with the new Atacama large Millimetre/ submillimetre Array – or ALMA for short – at the Atacama Desert in Chile, will be complimented by those made by the Green Bank Telescope whose survey boasts the added advantage of quick surveys of entire galaxies and the various structures within them.
Images courtesy of Bill Saxton (NRAO/AUI/NSF) & Hubble/NASA (top) and NRAO/AUI (bottom)