The Herschel space observatory has made detailed observations of surprisingly hot gas that may be orbiting or falling towards the supermassive black hole lurking at the center of our Milky Way galaxy. Herschel is a European Space Agency mission with important NASA participation.
“The black hole appears to be devouring the gas,” said Paul Goldsmith, the U.S. project scientist for Herschel at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “This will teach us about how supermassive black holes grow.”
Our galaxy’s black hole is located in a region known as Sagittarius A* — or Sgr A* for short — which is a nearby source of radio waves. The black hole has a mass about four million times that of our sun and lies roughly 26,000 light-years away from our solar system…
Astronomers have found evidence that galaxies are connected via an enormous cosmic web of intergalactic gas that helps many of them stay prolific star creators. Researchers studied the space between two nearby spiral galaxies, the Andromeda Galaxy and M33, which are 750,000 light-years apart and lie 2.5 million and 2.8 million light-years from Earth, respectively.
As the scientists report online recently in Nature, a previously known gaseous column between the two galaxies contains seven gas clouds (white blobs in the image), the largest being 21,000 light-years across. Made mostly of neutral hydrogen gas, the clouds have probably condensed from the filament of gas stretching between the two galaxies. This discovery suggests that even as galaxies turn their gas into stars, they grab more gas from their surroundings and thereby prolong their star-making careers.
Newly Discovered variety of Dark Matter Could From ‘Dark Atoms’
by Charles Q. Choi
The mysterious dark matter that makes up most of the matter in the universe could be composed, in part, of invisible and nearly intangible counterparts of atoms, protons and electrons, researchers say.
Dark matter is an invisible substance thought to make up five-sixths of all matter in the universe. Scientists inferred the existence of dark matter via its gravitational effects on the movements of stars and galaxies.
Most researchers think dark matter is composed of a new type of particle, one that interacts very weakly at best with all the known forces of the universe save gravity. As such, dark matter can almost never be seen or touched, and rarely even collides with itself…
Data from NASA’s Chandra X-ray Observatory have been used to discover 26 black hole candidates in the Milky Way’s galactic neighbor, Andromeda, as described in our latest press release. This is the largest number of possible black holes found in a galaxy outside of our own.
A team of researchers, led by Robin Barnard of the Harvard-Smithsonian Center for Astrophysics, used 152 observations of Chandra spanning over 13 years to find the 26 new black hole candidates. Nine were known from earlier work. These black holes belong to the stellar-mass black hole category, which means they were created when a massive star collapsed and are about 5 to 10 times the mass of the Sun…
Astronomers using a world-wide collection of telescopes have discovered the most prolific star factory in the Universe, surprisingly in a galaxy so distant that they see as it was when the Universe was only six percent of its current age.
The galaxy, dubbed HFLS3, 12.8 billion light-years from Earth, is producing the equivalent of nearly 3,000 Suns per year, a rate more than 2,000 times that of our own Milky Way. The galaxy is massive, with a huge reservoir of gas from which to form new stars.
“This is the most detailed look into the physical properties of such a distant galaxy ever made,” said Dominik Riechers, of Cornell University. “Getting detailed information on galaxies like this is vitally important to understanding how galaxies, as well as groups and clusters of galaxies, formed in the early Universe,” he added…
This composite image shows the galaxy cluster 1E 0657-56, also known as the “bullet cluster.” This cluster was formed after the collision of two large clusters of galaxies, the most energetic event known in the universe since the Big Bang.
Hot gas detected by Chandra in X-rays is seen as two pink clumps in the image and contains most of the “normal,” or baryonic, matter in the two clusters. The bullet-shaped clump on the right is the hot gas from one cluster, which passed through the hot gas from the other larger cluster during the collision.
An optical image from Magellan and the Hubble Space Telescope shows the galaxies in orange and white. The blue areas in this image show where astronomers find most of the mass in the clusters. The concentration of mass is determined using the effect of so-called gravitational lensing, where light from the distant objects is distorted by intervening matter. Most of the matter in the clusters (blue) is clearly separate from the normal matter (pink), giving direct evidence that nearly all of the matter in the clusters is dark…
Twist in Tale of Dark Matter hints at Shadow Milky Way
by Lisa Grossman
THE HUNT for some of the most wanted stuff in the universe took a new twist this week with the first results from a high-profile, space-based dark matter detector. The results are inconclusive, but, if combined with recent theory, they hint at something exciting. Could the universe have a dark side, complete with its own force, a zoo of particles and even a shadow version of the Milky Way?
“There could be a mirror world where interesting things are going on,” says James Bullock of the University of California at Irvine, who has been working on the idea of a “dark sector” for a while. “It means nature is much richer than we would otherwise know,” he says.
The dark sector could help explain why we’ve failed to detect dark matter on Earth so far, but it would also demand a radical shift in our understanding of the stuff.
The way stars and galaxies move shows there is more mass present than we can see. To account for this, 80 per cent of the universe’s matter must be dark. No wonder physicists are desperate to find it. The trouble is the stuff stubbornly refuses to interact with ordinary matter, except through gravity, so has not been conclusively detected…
This false-color composite image shows the Cartwheel galaxy as seen by the Galaxy Evolution Explorer’s far ultraviolet detector (blue); the Hubble Space Telescope’s wide field and planetary camera 2 in B-band visible light (green); the Spitzer Space Telescope’s infrared array camera at 8 microns (red); and the Chandra X-ray Observatory’s advanced CCD imaging spectrometer-S array instrument (purple).
Approximately 100 million years ago, a smaller galaxy plunged through the heart of Cartwheel galaxy, creating ripples of brief star formation. In this image, the first ripple appears as an ultraviolet-bright blue outer ring. The blue outer ring is so powerful in the Galaxy Evolution Explorer observations that it indicates the Cartwheel is one of the most powerful UV-emitting galaxies in the nearby universe.
The blue color reveals to astronomers that associations of stars 5 to 20 times as massive as our sun are forming in this region. The clumps of pink along the outer blue ring are regions where both X-rays and ultraviolet radiation are superimposed in the image. These X-ray point sources are very likely collections of binary star systems containing a blackhole (called massive X-ray binary systems). The X-ray sources seem to cluster around optical/ultraviolet-bright supermassive star clusters…
Simulations indicate that Milky Way galaxy may have up to 2000 black holes in its halo
by Bob Yirka
Valery Rashkov and Piero Madau, space scientists with the University of California have uploaded a paper to the preprint server arXiv in which they suggest that the Milky Way galaxy likely has between 70 and 2000 intermediate-mass black holes (IMBHs) existing in its outer edges. They came to this conclusion by building a computer model that mimics what they believe occurred when galaxies, and by extension, black holes merged during their formative years.
In building their simulation, the researchers began with the idea that when galaxies form, they have a “seed” black hole at their center. Over time, they suggest, some early galaxies ran into one another, merging as they did so, causing the black holes at their respective centers to merge as well. But not all couplings worked out, their simulations show. Because of gravitational waves created by such collisions, smaller black holes could be ejected, and would as a result, travel all the way to the outer reaches of the galaxy where they would reside alone in space…
Small Magellenic Cloud: A Confetti-Like Collection of Stars
by JPL staff
The tip of the “wing” of the Small Magellanic Cloud galaxy is dazzling in this new view from NASA’s Great Observatories. The Small Magellanic Cloud, or SMC, is a small galaxy about 200,000 light-years way that orbits our own Milky Way spiral galaxy.
The colors represent wavelengths of light across a broad spectrum. X-rays from NASA’s Chandra X-ray Observatory are shown in purple; visible-light from NASA’s Hubble Space Telescope is colored red, green and blue; and infrared observations from NASA’s Spitzer Space Telescope are also represented in red.
The spiral galaxy seen in the lower corner is actually behind this nebula. Other distant galaxies located hundreds of millions of light-years or more away can be seen sprinkled around the edge of the image…
I find all galaxies to be beautiful, from huge, symmetric elliptical puffballs to glorious, grand design spirals. But man, J082354.96 is seriously messed up. It’s still beautiful, though.
Wow. It’s quite the train wreck, and can definitely be labeled as “peculiar”. That’s an actual galaxy type, along with elliptical, disk (or spiral, like our Milky Way), and irregular. That last is for galaxies with no overall shape; peculiars have a definite shape, just a weird one.
J08 is about 650 million light years away, and clearly has something going on to give it this weird, drawn out, and oddly pleasing curvy hooked shape. To any astronomer’s eye, it’s obviously undergone an interaction: a cosmic collision with or nearby pass of another galaxy. That will commonly elongate a galaxy like this, and even cause those curls at the ends. As two galaxies collide (and sometimes merge), the huge collective gravities of each stretch the other out like taffy, and an off-center collision can cause vast arcs of gas and stars to be drawn out…
This pretty sprinkling of bright blue stars is the cluster NGC 2547, a group of recently formed stars in the southern constellation of Vela (The Sail). This image was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.
The Universe is an old neighbourhood — roughly 13.8 billion years old. Our galaxy, the Milky Way, is also ancient — some of its stars are more than 13 billion years old. Nevertheless, there is still a lot of action: new objects form and others are destroyed. In this image, you can see some of the newcomers, the young stars forming the cluster NGC 2547. But, how young are these cosmic youngsters really?
Although their exact ages remain uncertain, astronomers estimate that NGC 2547’s stars range from 20 to 35 million years old. That doesn’t sound all that young, after all. However, our Sun is 4600 million years old and has not yet reached middle age. That means that if you imagine that the Sun as a 40 year-old person, the bright stars in the picture are three-month-old babies…
W3 is an enormous stellar nursery about 6,200 light-years awayin the Perseus Arm…
one of the Milky Way galaxy’s main spiral arms, which hosts both low- and high-mass star formation. In this image from the Herschel space observatory, the low-mass forming stars are seen as tiny yellow dots embedded in cool red filaments, while the highest-mass stars — with greater than eight times the mass of our sun — emit intense radiation, heating up the gas and dust around them and appearing here in blue.
This 27-hour cumulative exposure photograph shows just how strongly these two galaxies are interacting. Shells, plumes, arcs of stars and even shared dust lanes are some of the features that highlight this very deep image. NGC 3169 on the left appears to be literally unraveling before our eyes. Perhaps the arc of star clumps below the pair are the remnants of a smaller galaxy that orbited both of them.
The initial view linked above is the “zoomed out” view. A landscape presentation of the pair as well as the full resolution view are available by clicking the icons beneath. Finally a grayscale image shows the full extent of the tidal tails.
Image: Adam Block/Mount Lemmon SkyCenter/University of Arizona [high-resolution]