Wind bubble found around young super star cluster
UCLA NEWS RELEASE
Posted: June 11, 2001
An international team of astronomers has detected a wind bubble associated with a super star cluster in a nearby galaxy -- a key indicator that helps explain how this extremely young cluster is evolving.
The findings of the team, which includes Lucian P. Crosthwaite and David S. Meier, UCLA graduate students, and Sara C. Beck of Tel Aviv University, were reported at the meeting of the American Astronomical Society in Pasadena, CA. The discovery, supported by funding from the National Science Foundation, the U.S.-Israel Binational Science Foundation, and the Sigma Xi Society, was made with infrared data taken at the W. M. Keck Observatory in Hawaii, operated jointly by the University of California and the California Institute of Technology, with support from NASA.
"We're measuring wind speeds of about 3000 miles per minute in the hydrogen gas," says Crosthwaite. "These are not unusual speeds for stellar winds. But stellar winds normally involve only a little mass. This wind is exceptional because it is pushing a million earth masses of gas, so it's far more powerful than what we have seen before".
"We estimate from its current rate of expansion that this phase of the life of the super star cluster can last at most 15,000 years, unless gravity is slowing the expansion, which is likely," says Meier. "Even so, the wind bubble is expanding rapidly and the shock waves from the bubble may prevent future star formation near the cluster."
Super star clusters were formed in the Milky Way billions of years ago, and were more common in the early universe. The effects of these luminous young clusters on galaxies are unknown. According to Beck, "We've known for some time that galaxies undergoing bursts of star formation make super star clusters and we've suspected that the winds of these clusters could affect the evolution of the parent galaxies. But this is a short-lived phase in the life of the cluster so it's hard to catch one in the act. We are lucky that NGC 5253 is at the right place and the right time for us to detect this extraordinary wind-blown bubble."
The Hubble Space Telescope's majestic view of the Eskimo Nebula. This spectacular poster is available now from the Astronomy Now Store.