Millions Of Black Holes And Quasars Found In Hot DOGs!
With its all-sky infrared survey, NASA's Wide-field Infrared Survey Explorer, or WISE, has identified millions of quasar candidates. Image credit: NASA/JPL-Caltech/UCLA
Nope. It’s not the latest craze in snack foods. The millions of quasar candidates and black holes have been located.
Found by NASA’s Wide-field Infrared Survey Explorer (WISE) mission they have been uncovered in extreme galaxies called hot DOGs, or dust-obscured galaxies. The incredible images peers through obscuration – even on the other side of the Universe.
Not only has this new survey unveiled a gargantuan supply of dusty black hole candidates, but it has also pinpointed nearly a thousand even dustier objects which are surmised to be some of the brightest galaxies ever located.These powerhouse galaxies radiate in the infrared and are affectionately known as hot DOGs.
“WISE has exposed a menagerie of hidden objects,” said Hashima Hasan, WISE program scientist at NASA Headquarters in Washington. “We’ve found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known and now, supermassive black holes and galaxies hiding behind cloaks of dust.”
The WISE survey, which was completed at the beginning of 2011, did a double-take on the entire visible sky. Its millions of images and exhaustive data set are all part of public record. This innovation has allowed astronomers all over the world, both amateur and professional, the freedom to study and make new discoveries.
Artist's concept of the Wide-field Infrared Survey Explorer (Photo credit: Wikipedia)
“The Wide-field Infrared Survey Explorer (WISE) is an extremely capable and efficient black hole finder.” says Daniel Stern (et al). “Optical and soft X-ray surveys alone are highly biased towards only unobscured AGN, while this simple WISE selection likely identifies even heavily obscured, Compton-thick AGN. Using deep, public data in the COSMOS field, we explore the properties of WISE-selected AGN candidates.”
With these new findings, astronomers hope to further understand how galaxies and their attendant black holes play out their lives… from growth the the cessation of star formation. One study alone turned up some two and half million active supermassive black holes which ranged in distances of up to ten billion light years away.
Out of these new objects, only about two-thirds are cataloged, simply because interstellar dust blocks their signature. Thanks to WISE and its infrared capabilities, these distant denizens are easily distinguished. One of the main goals of the mission was to pick them out – and nearly a thousand candidates have come forward.
“We’ve got the black holes cornered,” said Daniel Stern of NASA’s Jet Propulsion Laboratory, Pasadena, California, lead author of the WISE black hole study and project scientist for another NASA black-hole mission, the Nuclear Spectroscopic Telescope Array (NuSTAR). “WISE is finding them across the full sky, while NuSTAR is giving us an entirely new look at their high-energy X-ray light and learning what makes them tick.”
A Dusty Problem
So just how extreme is a Dust Obscured Galaxy? Try one that pumps out more than a hundred trillion times as much of the electromagnetic spectrum as the Sun. However, they only appear in the longest wavelengths of infrared… a light captured by WISE. Once seen, they weren’t forgotten and NASA’s Spitzer Space Telescope went to work following up on their discovery. Old DOGs do new tricks and not only are they home to supermassive black holes feeding on gas and dust, but they are also busy creating new stars.
More than a hundred of these objects, located about 10 billion light-years away, have been confirmed using the W.M. Keck Observatory on Mauna Kea, Hawaii, as well as the Gemini Observatory in Chile, Palomar’s 200-inch Hale telescope near San Diego, and the Multiple Mirror Telescope Observatory near Tucson, Arizona.
The Chicken and Egg Problem
“These dusty, cataclysmically forming galaxies are so rare WISE had to scan the entire sky to find them,” said Peter Eisenhardt, lead author of the paper on the first of these bright, dusty galaxies, and project scientist for WISE at JPL. “We are also seeing evidence that these record setters may have formed their black holes before the bulk of their stars. The ‘eggs’ may have come before the ‘chickens.’”
Hungry, yet? Because there is more… The WISE observations were combined with data at even longer infrared wavelengths from Caltech’s Submillimeter Observatory atop Mauna Kea, revealing these extreme galaxies are more than twice as hot as other infrared-bright galaxies. These “cooking” galaxies appear to be heated by an intense burst of activity from a supermassive black hole.
“We may be seeing a new, rare phase in the evolution of galaxies,” said Jingwen Wu of JPL, lead author of the study on the submillimeter observations. All three papers are being published in the Astrophysical Journal.
Original Story Source: NASA WISE News Release.
