NASA's WISE Finds Most Luminous Galaxy in Universe

Posted by pt91 at May 22, 2015 09:16 AM |
University of Leicester scientist in dazzling discovery

Issued by University of Leicester Press Office on 21 May 2015

Artist's concept image of the ‘Dusty 'Sunrise' at Core of Galaxy’ (credit: NASA/JPL-Caltech) available from: https://caltech.box.com/s/w01xeemil4shu2svtzpjkymfra8g795f

Caption in Notes to Editors.

A remote galaxy shining brightly with infrared light equal to more than 300 trillion suns has been discovered using data from NASA's Wide-field Infrared Survey Explorer, or WISE. The galaxy, which belongs to a new class of objects recently discovered by WISE -- nicknamed extremely luminous infrared galaxies, or ELIRGs -- is the most luminous galaxy found to date.

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

Professor Andrew Blain, from the University of Leicester’s Department of Physics and Astronomy, has been involved with WISE since its inception in 2001, and has been responsible for examining and validating the data from the WISE telescope.  He is a co-author of the new report into this discovery.

The galaxy, known as WISE J224607.57-052635.0, may have a behemoth black hole at its belly, gorging itself on gas.

Supermassive black holes grow by drawing gas and matter into a disk around them. The disk heats up to beyond-sizzling temperatures of millions of degrees, 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.

Immense black holes are common at the cores of galaxies, but finding one this big so far back in the cosmos is rare. Because light from the galaxy hosting the black hole has traveled 12.5 billion years to reach us, astronomers are seeing the object as it was in the past. The black hole was already billions of times the mass of our sun when our universe was only a tenth of its present age of 13.8 billion years.

"The massive black holes in ELIRGs could be gorging themselves on more matter for a longer period of time," said Professor Blain. "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 hundreds of other, similar oddball galaxies from infrared images of the entire sky it took 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, which are even more luminous than the ultraluminous infrared galaxies (ULIRGs) reported before, 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.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages, and operates, WISE for NASA's Science Mission Directorate. The spacecraft was put into hibernation mode in 2011 after it scanned the entire sky twice, completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify  potentially hazardous near-Earth objects.

For more information on WISE, visit:

http://www.nasa.gov/wise

-end-

Notes to Editors:

Professor Andrew Blain will be available by e-mail only from the afternoon of Friday 22 May. Contact: ab520@leicester.ac.uk

Felicia Chou

Headquarters, Washington

202-358-0257

felicia.chou@nasa.gov

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov

Image caption:

Dusty 'Sunrise' at Core of Galaxy (Artist's Concept)- available from https://caltech.box.com/s/w01xeemil4shu2svtzpjkymfra8g795f

This artist's concept depicts the current record holder for the most luminous galaxy in the universe. The galaxy, named WISE J224607.57-052635.0, is erupting with light equal to more than 300 trillion suns. It was discovered by NASA's Wide-Field Infrared Survey Explorer, or WISE. The galaxy is smaller than the Milky Way, yet puts out 10,000 times more energy.

Scientists think that a supermassive black hole at the center of this dusty galaxy is busily consuming gaseous material in a colossal growth spurt. As the gas is dragged toward the black hole, it heats up and blasts out visible, ultraviolet and X-ray light. The dust swaddling the galaxy absorbs this light and heats up, radiating longer-wavelength, infrared light. The dust also blocks our view of shorter, visible-light wavelengths, while letting longer-wavelengths through. This is similar to what happens when sunlight streams through our dusty atmosphere, producing a brilliant red sunrise.

In fact, over 99 percent of the light escaping from this dusty galaxy is infrared. As a result, it is much harder to see with optical telescopes.

Because light from the galaxy hosting the black hole has traveled 12.5 billion years to reach us, astronomers are seeing the object as it was in the distant past. During this epoch, galaxies would have been more than five times closer together than they are now, as illustrated in the background of the artist's concept. This is due to the expansion of space -- space itself and the galaxies in it are stretching apart from each other at ever-increasing speeds.

Image credit: NASA/JPL-Caltech

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