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NASA's WISE Survey Uncovers Millions Of Black Holes
#1
WASHINGTON -- NASA's Wide-field Infrared Survey Explorer (WISE) mission
has led to a bonanza of newfound supermassive black holes and extreme
galaxies called hot DOGs, or dust-obscured galaxies.



Images from the telescope have revealed millions of dusty black hole
candidates across the universe and about 1,000 even dustier objects
thought to be among the brightest galaxies ever found. These powerful
galaxies that burn brightly with infrared light are nicknamed 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."

WISE scanned the whole sky twice in infrared
light, completing its survey in early 2011. Like night-vision goggles
probing the dark, the telescope captured millions of images of the sky.
All the data from the mission have been released publicly, allowing
astronomers to dig in and make new discoveries.

The latest
findings are helping astronomers better understand how galaxies and the
behemoth black holes at their centers grow and evolve together. For
example, the giant black hole at the center of our Milky Way galaxy,
called Sagittarius A*, has 4 million times the mass of our sun and has
gone through periodic feeding frenzies where material falls towards the
black hole, heats up, and irradiates its surroundings. Bigger central
black holes, up to a billion times the mass of our sun, even may shut
down star formation in galaxies.

In one study, astronomers
used WISE to identify about 2.5 million actively feeding supermassive
black holes across the full sky, stretching back to distances more than
10 billion light-years away. About two-thirds of these black holes never
had been detected before because dust blocks their visible light. WISE
easily sees these monsters because their powerful, accreting black holes
warm the dust, causing it to glow in infrared light.

In two
other WISE papers, researchers report finding what are among the
brightest galaxies known, one of the main goals of the mission. So far,
they have identified about 1,000 candidates.

These extreme
objects can pour out more than 100 trillion times as much light as our
sun. They are so dusty, however, that they appear only in the longest
wavelengths of infrared light captured by WISE. NASA's Spitzer Space
Telescope followed up on the discoveries in more detail and helped show
that, in addition to hosting supermassive black holes feverishly
snacking on gas and dust, these DOGs are busy churning out new stars.



"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.'"



More than 100 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, Ariz.

The WISE observations combined
with data at even longer infrared wavelengths from Caltech's
Submillimeter Observatory atop Mauna Kea, Hawaii, revealed that these
extreme galaxies are more than twice as hot as other infrared-bright
galaxies. One theory is their dust is being heated by an extremely
powerful burst of activity from the 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.


For more information about WISE, visit:

http://www.nasa.gov/wise
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 سپاس شده توسط Behnaz ، crux
#2
دوستان نظری در مورد اینجور پستا ک براتون میذارم ندارین ؟

انتقادی ، پیشنهادی اگه داشته باشید استقبال میکنم
ممنون
در مورد اظهار نظر آقایون در تاپیک دلخوری باید بگم:
آقایون: کم گوی و گزیده گوی چون در// تا ز اندک تو جهان شود پر!!!
هرچند ک کلام گوهر بار از زبان شما جاری نشده، نمیشود و نخواهد شد!!!
پاسخ


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