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Posts Tagged ‘galaxy’

NASA’s Black-Hole-Hunter Catches Its First 10 Supermassive Black Holes

September 10, 2013 Leave a comment

Sep. 9, 2013 — NASA’s black-hole-hunter spacecraft, the Nuclear Spectroscopic Telescope Array, or NuSTAR, has “bagged” its first 10 supermassive black holes. The mission, which has a mast the length of a school bus, is the first telescope capable of focusing the highest-energy X-ray light into detailed pictures.

 

An optical color image of galaxies is seen here overlaid with X-ray data (magenta) from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR). (Credit: NASA/JPL-Caltech)
 

The new black-hole finds are the first of hundreds expected from the mission over the next two years. These gargantuan structures — black holes surrounded by thick disks of gas — lie at the hearts of distant galaxies between 0.3 and 11.4 billion light-years from Earth.

“We found the black holes serendipitously,” explained David Alexander, a NuSTAR team member based in the Department of Physics at Durham University in England and lead author of a new study appearing Aug. 20 in The Astrophysical Journal. “We were looking at known targets and spotted the black holes in the background of the images.”

Additional serendipitous finds such as these are expected for the mission. Along with the mission’s more targeted surveys of selected patches of sky, the NuSTAR team plans to comb through hundreds of images taken by the telescope with the goal of finding black holes caught in the background.

 

Read more: http://www.sciencedaily.com/releases/2013/09/130909154918.htm

NASA’s Chandra Observatory Catches Giant Black Hole Rejecting Material

September 2, 2013 Leave a comment

Aug. 29, 2013 — Astronomers using NASA’s Chandra X-ray Observatory have taken a major step in explaining why material around the giant black hole at the center of the Milky Way Galaxy is extraordinarily faint in X-rays. This discovery holds important implications for understanding black holes.

Supermassive black hole Sagittarius A* at the heart of the Milky Way galaxy. (Credit: X-ray: NASA/UMass/D.Wang et al., IR: NASA/STScI)

New Chandra images of Sagittarius A* (Sgr A*), which is located about 26,000 light-years from Earth, indicate that less than 1 percent of the gas initially within Sgr A*’s gravitational grasp ever reaches the point of no return, also called the event horizon. Instead, much of the gas is ejected before it gets near the event horizon and has a chance to brighten, leading to feeble X-ray emissions.

These new findings are the result of one of the longest observation campaigns ever performed with Chandra. The spacecraft collected five weeks’ worth of data on Sgr A* in 2012. The researchers used this observation period to capture unusually detailed and sensitive X-ray images and energy signatures of super-heated gas swirling around Sgr A*, whose mass is about 4 million times that of the sun.

Read more: http://www.sciencedaily.com/releases/2013/08/130829142311.htm

Largest Quasar Ever Discovered Burns 100 Times Brighter Than Entire Milky Way

November 29, 2012 Leave a comment

By Emily Elert Posted 11.28.2012
 
Glowing galactic center located near a supermassive black hole
Artist's Rendering of Huge Quasar Outflow

Artist’s Rendering of Huge Quasar Outflow ESO/L. Calçada

Astronomers have found a galaxy whose super-luminous nucleus–called a quasar–is burning 100 times as much energy as the entire Milky Way galaxy.

Though theory has long predicted that quasars this powerful should exist, the newly-discovered object, known as SDSS J1106+1939, is by far the most energetic ever observed. The quasar is powered by a supermassive black hole that lies at its center.

Read more: http://www.popsci.com/science/article/2012-11/scientists-discover-biggest-quasar-ever-near-supermassive-black-hole

Planck spots hot gas bridging galaxy cluster pair

November 22, 2012 1 comment

Planck spots hot gas bridging galaxy cluster pair

 
Galaxy clusters connected by gas bridge

 20 November 2012
ESA’s Planck space telescope has made the first conclusive detection of a bridge of hot gas connecting a pair of galaxy clusters across 10 million light-years of intergalactic space.
 
Planck’s primary task is to capture the most ancient light of the cosmos, the Cosmic Microwave Background, or CMB. As this faint light traverses the Universe, it encounters different types of structure including galaxies and galaxy clusters – assemblies of hundreds to thousands of galaxies bound together by gravity.

If the CMB light interacts with the hot gas permeating these huge cosmic structures, its energy distribution is modified in a characteristic way, a phenomenon known as the Sunyaev–Zel’dovich (SZ) effect, after the scientists who discovered it.

This effect has already been used by Planck to detect galaxy clusters themselves, but it also provides a way to detect faint filaments of gas that might connect one cluster to another.

In the early Universe, filaments of gaseous matter pervaded the cosmos in a giant web, with clusters eventually forming in the densest nodes.

Much of this tenuous, filamentary gas remains undetected, but astronomers expect that it could most likely be found between interacting galaxy clusters, where the filaments are compressed and heated up, making them easier to spot.

 Read more: http://www.esa.int/SPECIALS/Planck/SEMRT791M9H_0.html

NASA locates most distant galaxy ever discovered

November 19, 2012 Leave a comment

The most distant galaxy ever seen in the universe has been detected by NASA’s Hubble and Spitzer space telescopes.

The most distant galaxy ever seen in the universe has been detected by NASA's Hubble and Spitzer space telescopes.

The newly discovered galaxy, named MACS0647-JD, is very young and only a tiny fraction of the size of our Milky Way Photo: Nasa

By , Science Correspondent

11:58AM GMT 16 Nov 2012

Light from the newly discovered galaxy, which astronomers have named MACS0647-JD, reached Earth after travelling across space for 13.3 billion years.

It provides a window on what the galaxy looked like just 420 million years after the big bang, when the universe was only three per cent of its current age.

The galaxy was detected using an effect known as gravitational lensing, where large clusters of galaxies are used as “natural zoom lenses” to enlarge the appearance of galaxies behind them.

Astronomers were able to detect a hint of light from MACS0647-JD because it was magnified as it passed around an enormous galaxy cluster known as MACS J0647+7015 as it travelled towards Earth.

Thanks to the gravitational force of the cluster, the Hubble telescope was able to detect the light at up to eight times the brightness it otherwise would.

Read more: http://www.telegraph.co.uk/science/space/9682959/NASA-locates-most-distant-galaxy-ever-discovered.html

 

Gravitational lens magnifies earliest galaxy yet seen

November 17, 2012 Leave a comment

by  – Nov 17 2012, 8:45pm GTBST

Small galaxy was producing stars only 425 million years after the Big Bang.

 

The contours of the gravitational lens (colored lines) along with the three images of the distant background galaxy (JD1-3).

The Universe’s first galaxies played a key role in shaping the environment in which we now find ourselves. They fostered the formation of the first stars, which died in spectacular explosions that enabled a new generation of smaller stars, orbited by rockier planets. And the galaxies themselves merged and grew, forming the large galaxies and clusters that populate the Universe today. But, despite their critical role in shaping the Universe, we’ve never actually been able to see one of them.

Slowly, that’s changing. The Hubble Deep Field exposures have helped us spot galaxies from the Universe’s early days. But now, a special Hubble project has used an intervening cluster of galaxies as a lens to spot what appears to be the most distant galaxy ever imaged, one that dates from just 425 million years after the Big Bang.

Since it takes light time to reach us from distant corners of the Universe, the further you look, the older the objects you see. The wavelength of the light also gets shifted towards the red by the expansion of the Universe, which stretches it out as it travels. As you get closer to the Big Bang, light that started out in the UV end of the spectrum gets pushed deeper and deeper into the infrared. To make these galaxies even harder to spot, the extreme distance means that very few photons actually make their way to Earth, so these objects are incredibly dim.

Read more: http://arstechnica.com/science/2012/11/gravitational-lens-magnifies-earliest-galaxy-yet-seen/

 

NASA’s Cassini Sees Burp at Saturn After Large Storm

November 16, 2012 Leave a comment

These red, orange and green clouds (false color) in Saturn's northern hemisphere indicate the tail end of a  massive storm

These red, orange and green clouds (false color) in Saturn’s northern hemisphere indicate the tail end of a massive storm that started in December 2010. Even after visible signs of the storm started to fade, infrared measurements continued to reveal powerful effects at work in Saturn’s stratosphere. Image credit:NASA/JPL-Caltech/Space Science Institute
› Full image and caption

October 25, 2012

PASADENA, Calif. — NASA’s Cassini spacecraft has tracked the aftermath of a rare massive storm on Saturn. Data reveal record-setting disturbances in the planet’s upper atmosphere long after the visible signs of the storm abated, in addition to an indication the storm was more forceful than scientists previously thought.

Data from Cassini’s composite infrared spectrometer (CIRS) instrument revealed the storm’s powerful discharge sent the temperature in Saturn’s stratosphere soaring 150 degrees Fahrenheit (83 kelvins) above normal. At the same time, researchers at NASA’s Goddard Spaceflight Center in Greenbelt, Md., detected a huge increase in the amount of ethylene gas, the origin of which is a mystery. Ethylene, an odorless, colorless gas, isn’t typically observed on Saturn. On Earth, it is created by natural and man-made sources.

Goddard scientists describe the unprecedented belch of energy in a paper to be published in the Nov. 20 issue of the Astrophysical Journal.

“This temperature spike is so extreme it’s almost unbelievable, especially in this part of Saturn’s atmosphere, which typically is very stable,” said Brigette Hesman, the study’s lead author and a University of Maryland scientist who works at Goddard. “To get a temperature change of the same scale on Earth, you’d be going from the depths of winter in Fairbanks, Alaska, to the height of summer in the Mojave Desert.”

Read more: http://www.jpl.nasa.gov/news/news.php?release=2012-335&rn=news.xml&rst=3564