sexta-feira, 27 de março de 2015

SUZAKU, HERSCHEL LINK A BLACK-HOLE "WIND" TO A GALACTIC GUSH OF STAR-FORMING GAS

By combining observations from the Japan-led Suzaku X-ray satellite and the European Space Agency's infrared Herschel Space Observatory, scientists have connected a fierce "wind" produced near a galaxy's monster black hole to an outward torrent of cold gas a thousand light-years across. The finding validates a long-suspected feedback mechanism enabling a supermassive black hole to influence the evolution of its host galaxy.

"This is the first study directly connecting a galaxy's actively 'feeding' black hole to features found at much larger physical scales," said lead researcher Francesco Tombesi, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park (UMCP). "We detect the wind arising from the luminous disk of gas very close to the black hole, and we show that it's responsible for blowing star-forming gas out of the galaxy's central regions."

This artist's rendering shows a galaxy being cleared of interstellar gas, the building blocks of new stars. New X-ray observations by Suzaku have identified a wind emanating from the black hole's accretion disk (inset) that ultimately drives such outflows.
Image Credit: 
ESA/ATG Medialab


Star formation takes place in cold, dense molecular clouds. By heating and dispersing gas that could one day make stars, the black-hole wind forever alters a large portion of its galaxy.

In a study published in the March 26 edition of Nature, Tombesi and his team report the connection in a galaxy known as IRAS F11119+3257, or F11119 for short. The galaxy is so distant, its light has been traveling to us for 2.3 billion years, or about half the present age of our solar system.

Like most galaxies, including our own Milky Way, F11119 hosts a supersized black hole, one estimated at 16 million times the sun's mass. The black hole's activity is fueled by a rotating collection of gas called an accretion disk, which is some hundreds of times the size of our planetary system. Closest to the black hole, the orbiting matter reaches temperatures of millions of degrees and is largely responsible for the galaxy's enormous energy output, which exceeds the sun's by more than a trillion times. The galaxy is heavily enshrouded by dust, so most of this emission reaches us in the form of infrared light.


A red-filter image of IRAS F11119+3257 (inset) from the University of Hawaii's 2.2-meter telescope shows faint features that may be tidal debris, a sign of a galaxy merger. Background: A wider view of the region from the Sloan Digital Sky Survey.
Image Credit: 
NASA's Goddard Space Flight Center/SDSS/S. Veilleux


See: http://www.nasa.gov/content/goddard/suzaku-herschel-link-a-black-hole-wind-to-a-galactic-gush-of-star-forming-gas/?linkId=13124238&utm_content=buffer1dd02&utm_medium=social&utm_source=plus.google.com&utm_campaign=buffer#.VRYGm_ysVsI














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