Super Stellar Winds Powered By Intense Star Formation.
By utilizing observations from three telescopes, a team of astronomers located 29 objects with out flowing galactic winds that clocked in at up to 2,500 kilometers per second.That is an amazing order of magnitude faster than prior observations. These incredible winds are powered by a intense burst of star formation and may very well be responsible for blasting gas completely out of galaxies, rendering them unable to create new stars.
“They’re nearly blowing themselves apart,” said Aleksandar Diamond-Stanic, a fellow at the University of California’s Southern California Center for Galaxy Evolution, who led the study. “Most galactic winds are more like fountains; the out flowing gas will fall back onto the galaxies. With the high-velocity winds we’ve observed the outflowing gas will escape the galaxy and never return.” Diamond-Stanic and colleagues published their findings in Astrophysical Journal Letters.
When the researchers spotted these super stellar winds flowing outwards with speeds of 500 to 2,500 kilometers per second, they first thought they might be the product of quasars. However, the few billion light year distant typhoons seem to be coming directly from whole, young galaxies. These bright, neophyte star factories are currently producing – or just completing – a cycle of intense star formation.
An Explosive Situation
“These galactic-scale crazy-fast winds are probably driven by the really massive stars exploding and pushing out the gas around them,” said Alison Coil, professor in UC San Diego’s Center for Astrophysics and Space Sciences and a co-author of the paper. “There’s just such a high density of those stars it’s like all these bombs went off near each other at the same time. Each bomb evacuates the area around it, then the next can push gas out further until they’re evacuating gas on the scale of the whole galaxy.”
Such a high rate of speed isn’t common for galaxies of this type. Is it possible this is a new type of event, or is it just another phase of growing up? Astronomers aren’t sure since these types of observations are so brief, leaving them to wonder why star production can quickly end. A plausible explanation could be a supermassive black hole – an active galactic nuclei. AGNs are know to cause fierce stellar winds, blasting away the gas needed to form new stars. Thanks to these new observations, we’re able to speculate that black holes may not be the reason that some galaxies are depleted of stellar fuel.
“The winds seem to be powered by the starburst,” Diamond-Stanic said. “The central supermassive black hole is apparently just a spectator for these massive stellar fireworks.”
Original Story Source: University of San Diego News Release.