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NASA’s Black-Hole-Hunter Catches Its First 10 Supermassive Black Holes
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.
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
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.
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
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.
Planck spots hot gas bridging galaxy cluster pair
Planck spots hot gas bridging galaxy cluster pair
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
The most distant galaxy ever seen in the universe has been detected by NASA’s Hubble and Spitzer space telescopes.
By Nick Collins, 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.
Gravitational lens magnifies earliest galaxy yet seen
by John Timmer – Nov 17 2012, 8:45pm GTBST
Small galaxy was producing stars only 425 million years after the Big Bang.
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
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
NASA’s NuSTAR Spots Flare from Milky Way’s Black Hole
ScienceDaily (Oct. 23, 2012) — NASA’s newest set of X-ray eyes in the sky, the Nuclear Spectroscopic Telescope Array (NuSTAR), has caught its first look at the giant black hole parked at the center of our galaxy. The observations show the typically mild-mannered black hole during the middle of a flare-up.
“We got lucky to have captured an outburst from the black hole during our observing campaign,” said Fiona Harrison, the mission’s principal investigator at the California Institute of Technology (Caltech) in Pasadena. “These data will help us better understand the gentle giant at the heart of our galaxy and why it sometimes flares up for a few hours and then returns to slumber.”
The new images can be seen by visiting: http://www.nasa.gov/nustar .
Read more: http://www.sciencedaily.com/releases/2012/10/121023145224.htm
Earth-sized planet found just outside solar system
October 16, 2012 by Seth Borenstein
EnlargeThis artist’s impression shows the planet orbiting the star Alpha Centauri B, a member of the triple star system that is the closest to Earth. Alpha Centauri B is the most brilliant object in the sky and the other dazzling object is Alpha Centauri A. Our own Sun is visible to the upper right. The tiny signal of the planet was found with the HARPS spectrograph on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. Credit: ESO/L. Calçada
(Phys.org)—European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system—the nearest to Earth. It is also the lightest exoplanet ever discovered around a star like the Sun. The planet was detected using the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. The results will appear online in the journal Nature on 17 October 2012.
Alpha Centauri is one of the brightest stars in the southern skies and is the nearest stellar system to our Solar System—only 4.3 light-years away. It is actually a triple star—a system consisting of two stars similar to the Sun orbiting close to each other, designated Alpha Centauri A and B, and a more distant and faint red component known as Proxima Centauri. Since the nineteenth century astronomers have speculated about planets orbiting these bodies, the closest possible abodes for life beyond the Solar System, but searches of increasing precision had revealed nothing. Until now.
Read more: http://phys.org/news/2012-10-earth-sized-planet-solar.html
Large water reservoirs at the dawn of stellar birth
Herschel’s infrared view of part of the Taurus Molecular Cloud, within which the bright, cold pre-stellar cloud L1544 can be seen at the lower left. It is surrounded by many other clouds of gas and dust of varying density. The Taurus Molecular Cloud is about 450 light-years from Earth and is the nearest large region of star formation. The image covers a field of view of approximately 1 x 2 arcminutes. Credit: ESA/Herschel/SPIRE
ESA’s Herschel space observatory has discovered enough water vapour to fill Earth’s oceans more than 2000 times over, in a gas and dust cloud that is on the verge of collapsing into a new Sun-like star.
Stars form within cold, dark clouds of gas and dust – ‘pre-stellar cores’ – that contain all the ingredients to make solar systems like our own.
Water, essential to life on Earth, has previously been detected outside of our Solar System as gas and ice coated onto tiny dust grains near sites of active star formation, and in proto-planetary discs capable of forming alien planetary systems.
The new Herschel observations of a cold pre-stellar core in the constellation of Taurus known as Lynds 1544 are the first detection of water vapour in a molecular cloud on the verge of star formation.
More than 2000 Earth oceans-worth of water vapour were detected, liberated from icy dust grains by high-energy cosmic rays passing through the cloud.
Read more: http://phys.org/news/2012-10-large-reservoirs-dawn-stellar-birth.html
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