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NASA’s Great Observatories Begin Deepest Ever Probe Of The Universe

October 24, 2013 Leave a comment

Credit: NASA, ESA, and M. Postman (STScI), and the CLASH team

Credit: NASA, ESA, and M. Postman (STScI), and the CLASH team

NASA’s Great Observatories are teaming up to look deeper into the universe than ever before. With a boost from natural “zoom lenses” found in space, they should be able to uncover galaxies that are as much as 100 times fainter than what the Hubble, Spitzer, and Chandra space telescopes can typically see. This ambitious collaborative program is called The Frontier Fields. Astronomers will spend the next three years peering at six massive clusters of galaxies. Researchers are interested not only as to what’s inside the clusters, but also what’s behind them. The gravitational fields of the clusters brighten and magnify distant background galaxies that are so faint they would otherwise be unobservable.

Despite several deep field surveys, astronomers realized that a lot is still to be learned about the distant universe. And, such knowledge will help in planning the observing strategy for the next-generation space observatory, the James Webb Space Telescope.

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Sagittarius A*: A Glimpse Of The Violent Past Of Milky Way’s Giant Black Hole

October 24, 2013 1 comment

Researchers using NASA’s Chandra X-ray Observatory have found evidence that the normally dim region very close to the supermassive black hole at the center of the Milky Way Galaxy flared up with at least two luminous outbursts in the past few hundred years.

This discovery comes from a new study of rapid variations in the X-ray emission from gas clouds surrounding the supermassive black hole, a.k.a. Sagittarius A*, or Sgr A* for short. The scientists show that the most probable interpretation of these variations is that they are caused by light echoes.

The echoes from Sgr A* were likely produced when large clumps of material, possibly from a disrupted star or planet, fell into the black hole. Some of the X-rays produced by these episodes then bounced off gas clouds about thirty to a hundred light years away from the black hole, similar to how the sound from a person’s voice can bounce off canyon walls. Just as echoes of sound reverberate long after the original noise was created, so too do light echoes in space replay the original event.

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ALMA Reveals Ghostly Shape Of ‘Coldest Place In The Universe’

October 24, 2013 Leave a comment

Credit: Bill Saxton; NRAO/AUI/NSF; NASA/Hubble; Raghvendra Sahai

Credit: Bill Saxton; NRAO/AUI/NSF; NASA/Hubble; Raghvendra Sahai

At a cosmologically crisp one degree Kelvin (minus 458 degrees Fahrenheit), the Boomerang Nebula is the coldest known object in the Universe – colder, in fact, than the faint afterglow of the Big Bang, which is the natural background temperature of space.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have taken a new look at this intriguing object to learn more about its frigid properties and to determine its true shape, which has an eerily ghost-like appearance.

As originally observed with ground-based telescopes, this nebula appeared lopsided, which is how it got its name. Later observations with the Hubble Space Telescope revealed a bow-tie-like structure. The new ALMA data, however, reveal that the Hubble image tells only part of the story, and the twin lobes seen in that image may actually be a trick of the light as seen at visible wavelengths.

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Unique Chemical Composition Surrounding Supermassive Black Hole – A Step Toward Development Of New Black Hole Exploration Method

October 24, 2013 Leave a comment

The Atacama Large Millimeter/submillimeter Array (ALMA) successfully captured a detailed image of high density molecular gas around an active galactic nucleus harboring a supermassive black hole. The observations at the highest ever achieved reveal a unique chemical composition characterized by enhancement of hydrogen cyanide (HCN) around the black hole. An research team thought a high temperature affected by the black hole caused this peculiar chemical properties. The team expect that this unique chemical properties can be used to find black holes hidden behind dust.

The research findings are presented in the article “Submillimeter ALMA Observation of the Dense Gas in the Low-Luminosity Type-1 Active Nucleus of NGC 1097” published in the Publication of the Astronomical Society of Japan, Vol. 65, of October 25, 2013.

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