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Most luminous galaxy shining with the light of more than 300 trillion suns discovered

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Astronomers have stumbled upon the most luminous galaxy ever using data collected by NASA’s Wide-field Infrared Survey Explorer (WISE). According to NASA, the galaxy is shining with the light of more than 300 trillion suns and belongs to a new class of objects recently discovered by WISE — extremely luminous infrared galaxies, or ELIRGs.

The galaxy is known as WISE J224607.57-052635.0 and according to its discoverers, the distant galaxy may pack a behemoth black hole at its center. For those of you who are not aware, supermassive black holes gorge on gas and matter around them and on top of that they draw the gas and matter into a disk around them thereby heating the disk to roaring temperatures of millions of degrees and blasting out high-energy, visible, ultraviolet, and X-ray light. The light is blocked by surrounding cocoons of dust. As the dust heats up, it radiates infrared light.

“We are looking at a very intense phase of galaxy evolution,” said Chao-Wei Tsai of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, lead author of a new report appearing in the May 22 issue of The Astrophysical Journal. “This dazzling light may be from the main growth spurt of the galaxy’s black hole.”

It isn’t uncommon to spot galaxies with supermassive black holes at their center, but the reason this finding is special is because it is located some 12.5 billion years away from us. This means that the findings takes us “far back” in the cosmos – only a tenth of its present age. Even at that age, the black hole was already billions of times the mass of our sun.

According to astronomers there are three possible reasons why the black holes in the ELIRGs could have grown so massive. First, they may have been born big i.e. the “seeds,” or embryonic black holes, might be bigger than thought possible.

The second possible explanation is that the black hole broke the theoretical limit of black hole feeding, called the Eddington limit. When a black hole feeds, gas falls in and heats up, blasting out light. The pressure of the light actually pushes the gas away, creating a limit to how fast the black hole can continuously scarf down matter. If a black hole broke this limit, it could theoretically balloon in size at a breakneck pace. Black holes have previously been observed breaking this limit; however, the black hole in the study would have had to repeatedly break the limit to grow this large.

The third explanation is that the black holes might just be bending this limit.

“Another way for a black hole to grow this big is for it to have gone on a sustained binge, consuming food faster than typically thought possible,” said Tsai. “This can happen if the black hole isn’t spinning that fast.”

If a black hole spins slowly enough, it won’t repel its meal as much. In the end, a slow-spinning black hole can gobble up more matter than a fast spinner.

“The massive black holes in ELIRGs could be gorging themselves on more matter for a longer period of time,” said Andrew Blain of University of Leicester in the United Kingdom, a co-author of this report. “It’s like winning a hot-dog-eating contest lasting hundreds of millions of years.”

More research is needed to solve this puzzle of these dazzlingly luminous galaxies. The team has plans to better determine the masses of the central black holes. Knowing these objects’ true hefts will help reveal their history, as well as that of other galaxies, in this very crucial and frenzied chapter of our cosmos.

WISE has been finding more of these oddball galaxies in infrared images of the entire sky captured in 2010. By viewing the whole sky with more sensitivity than ever before, WISE has been able to catch rare cosmic specimens that might have been missed otherwise.

The new study reports a total of 20 new ELIRGs, including the most luminous galaxy found to date. These galaxies were not found earlier because of their distance, and because dust converts their powerful visible light into an incredible outpouring of infrared light.

“We found in a related study with WISE that as many as half of the most luminous galaxies only show up well in infrared light,” said Tsai.