December 10, 2013
New NRAO Telescope Instrument Gives Detailed Look At Galaxy M82
redOrbit Staff & Wire Reports - Your Universe Online
Astronomers have managed to get an up close and personal look at the nearby starburst galaxy M82, detecting concentrations of dense molecular gas surrounding regions of intense star formation and streams of material exiting the galaxy’s disk, the National Radio Astronomy Observatory (NRAO) announced Monday.
The new data comes courtesy of the high-frequency Robert C. Byrd Green Bank Telescope (GBT), the world's largest, fully-steerable telescope. Since M82 is located just 12 million light-years away, the NRAO deemed it an “ideal target” for the telescope’s new “W-Band receiver” – an instrument reportedly capable of detecting the millimeter wavelength light that is emitted by molecular gas.
“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,” explained lead author Amanda Kepley, a radio astronomer and post-doctoral fellow working out of the NRAO facility in Green Bank, West Virginia. “Having this new capability may help us understand why stars form where they do.”
Kepley and her colleagues, whose work has been accepted for publication in the Astrophysical Journal Letters, went on to explain that while scientists know there is a link between dense molecular gas and areas of star formation, little is known about the connection. Furthermore, they report that the relationship could actually vary in different types of galaxies.
“By creating wide-angle maps of the gas in galaxies, astronomers hope to better understand this complex interplay,” the NRAO said. “To date, however, these kinds of observations have not been easy since molecules that are used to map the distribution of dense gas… shine feebly in millimeter light. With its new W-Band receiver, the GBT was able to make highly 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,” added 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 telescope’s ability will allow astronomers to reduce the time required to survey whole galaxies, as well as quickly examine different components of those galaxies. These surveys would serve to complement higher-resolutions obtained using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile, the NRAO said.