SOFIA Spots Recent Starbursts in The Milky Way Galaxy's Center
WASHINGTON -- Researchers using the Stratospheric Observatory for Infrared Astronomy (SOFIA) have captured new images of a ring of gas and dust seven light-years in diameter surrounding the supermassive black hole at the center of the Milky Way, and of a neighboring cluster of extremely luminous young stars embedded in dust cocoons.
The images of our galaxy's circumlunar ring (CNR) and its neighboring quintuplet cluster (QC) are the subjects of two posters presented this week during the American Astronomical Society's meeting in Long Beach, Calif. Ryan Lau of Cornell University and his collaborators studied the CNR. Matt Hankins of the University of Central Arkansas in Conway is lead author of the other paper, regarding the QC.
SOFIA is a highly modified Boeing 747SP aircraft carrying a telescope with an effective diameter of 100 inches (2.54 meters) to altitudes as high as 45,000 feet (13.7 kilometers).
The images were obtained during SOFIA flights in 2011 with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) instrument built by a team with principal investigator Terry Herter of Cornell.
FORCAST offered astronomers the ability to see the CNR and QC regions and other exotic cosmic features whose light is obscured by water vapor in Earth's atmosphere and interstellar dust clouds in the mid-plane of the Milky Way. Neither ground-based observatories on tall mountain peaks nor NASA's orbiting Hubble and Spitzer space telescopes can see them.
"The focus of our study has been to determine the structure of the circumnuclear ring with the unprecedented precision possible with SOFIA" said Lau. "Using these data we can learn about the processes that accelerate and heat the ring."
The nucleus of the Milky Way is inhabited by a black hole with 4 million times the mass of the sun and is orbited by a large disk of gas and dust. The ring seen in Figure 1a is the inner edge of that disk. The galactic center also hosts several exceptionally large star clusters containing some of the most luminous young stars in the galaxy, one of which is the Quintuplet Cluster seen in Figure 2. The combination of SOFIA's airborne telescope with the FORCAST camera produced the sharpest images of those regions ever obtained at mid-infrared wavelengths, allowing discernment of new clues about what is happening near the central black hole.
"Something big happened in the Milky Way's center within the past 4 million to 6 million years which resulted in several bursts of star formation, creating the Quintuplet Cluster, the Central Cluster, and one other massive star cluster." said Hankins, lead author of the QC paper. "Many other galaxies also have so-called 'starbursts' in their central regions, some associated with central black holes, some not. The Milky Way's center is much nearer than other galaxies, making it easier for us to explore possible connections between the starbursts and the black hole."
http://www.nasa.gov/home/hqnews/2013/jan/HQ_13-010_SOFIA_Starbursts.html
