'Most Luminous Galaxy' in the Universe might rip apartAmy Walsh (Author) Published Date : Jan 17, 2016 23:19 IST
The most luminous galaxy in the Universe might be about to tear apart. A team of researchers used Atacama Large Millimeter/submillimeter Array, ALMA, to trace, for the first time, the actual motion of the galaxy's interstellar medium, the gas and dust between the stars and found a galaxy so chaotic that it is ripping itself apart.
It is so called obscured quasar 12.4 billion light-years away is so violently turbulent that it may eventually discard its entire supply of star-forming gas.
Tanio D az-Santos of the Universidad Diego Portales in Santiago, Chile, stated the above.
These properties make this object a beast in the infrared, said Roberto Assef, an astronomer with the Universidad Diego Portales and leader of the ALMA observing team.
Previous studies with NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft reveal that the galaxy, dubbed W2246-0526, is glowing in infrared light as intensely as approximately 350 trillion Suns.
We suspected that this galaxy was in a transformative stage of its life because of the enormous amount of infrared energy discovered with WISE, said Peter Eisenhardt with NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Evidence strongly suggests that this galaxy is an obscured quasar, a very distant galaxy with a voraciously feeding supermassive black hole at its center that is completely obscured behind a thick blanket of dust.
This galaxy's startling brightness is powered by a tiny, yet incredibly energetic disk of gas that is being superheated as it spirals in on the supermassive black hole. The light from this blazingly bright accretion disk is then absorbed by the surrounding dust, which re-emits the energy as infrared light.
The astronomers compare this turbulent action to a pot of boiling water. If these conditions continue, they say, the galaxy's intense infrared radiation will boil away all of its interstellar gas.
This galaxy belongs to a very unusual type of quasar known as Hot, Dust-Obscured Galaxies or Hot DOGs. The astronomers used ALMA to precisely map the motion of ionized carbon atoms throughout the entire galaxy. These atoms, which are tracers for interstellar gas, naturally emit infrared light, which becomes shifted to millimeter wavelengths as it travels the vast cosmic distances to Earth due to the expansion of the Universe.
Large amounts of ionized carbon were found in an extremely turbulent dynamic state throughout the galaxy, D az-Santos describes. The data reveal that this interstellar material is careening anywhere from 500 to 600 kilometers per second across the entire galaxy.
The astronomers believe that this turbulence is primarily due to the fact that the region around the black hole is at least 100 times more luminous than the rest of the galaxy combined; in other quasars, the proportion is much more modest. This intense yet localized radiation exerts tremendous pressure on the entire galaxy, to potentially devastating effect.
Current models of galactic dynamics combined with the ALMA data indicate that this galaxy is unstable and its interstellar gas is being blown away in all directions. This suggests that the galaxy's Hot DOG days are numbered as it matures into a more traditional unobscured quasar.
'Most Luminous Galaxy' in the Universe might rip apart