Hindustan Times
October 13, 2014
An Indian astronomer and her team at Johns Hopkins University in Baltimore, US has identified a galaxy 2.9 billion light-years away that's vigorously pumping out ultraviolet radiation. This discovery can help get a better understanding on the evolution of cosmos and exploration of new ones.
The galaxy in Ursa Major has been named J0921+4509. (Photo courtesy: NASA, ESA, R Overzier (ON/MCTI), T Heckman (JHU))
The discovery has been reported in the journal Science on Friday.
Sanchayeeta Borthakur and her colleagues used the cosmic origins spectrograph aboard NASA's Hubble space telescope to examine the galaxy named J0921+4509, which is located about three billion light-years away in Ursa Major.
"Our discovery of ionising radiation escaping galaxy J0921+4509 presents a viable and highly likely scenario where young stars can create gaps in their cloud blanket. And through these holes, extreme ultraviolet radiation capable of ionizing hydrogen can freely stream out. We believe that this is what is going on in the very first galaxies, "lead author Sanchayeeta Borthakur said.
Explaining the process she said, "This galaxy produced a billion solar masses of stars in a region of few hundred light years across and their combined force (in the form of stellar winds) blew part of the cloud cover. This creates tunnels for high energy extreme ultraviolet photons to escape.
"We used the Hubble space telescope to directly detect the escaping ionizing flux from this galaxy, she said, adding, "This is the first case in the nearby universe that we detected such a large escape fraction of 21% (the best nearby candidates have 1-3% escaping photons)."
No comments:
Post a Comment