Posted on by Tammy Plotner

Millisecond Pulsar Discovered In Rare Triple Star System

An illustration of the triple millisecond pulsar with its two white dwarf companions. According to the new model, this remarkable system has survived three phases of mass transfer and a supernova explosion, and yet it remained dynamically stable. Credit: Thomas Tauris

If you’re looking for something truly unique, then check out the cosmic menage aux trois ferreted out by a team of international astronomers using the Green Bank Telescope (GBT). This unusual group located in the constellation of Taurus includes a pulsar which is orbited by a pair of white dwarf stars. It’s the first time researchers have identified a triple star system containing a pulsar and the team has already employed the clock-like precision of the pulsar’s beat to observe the effects of gravitational interactions.

“This is a truly remarkable system with three degenerate objects. It has survived three phases of mass transfer and a supernova explosion, and yet it remained dynamically stable”, says Thomas Tauris, first author of the present study. “Pulsars have previously been found with planets and in recent years a number of peculiar binary pulsars were discovered which seem to require a triple system origin. But this new millisecond pulsar is the first to be detected with two white dwarfs.”

This wasn’t just a chance discovery. The observations of 4,200 light year distant J0337+1715 came from an intensive study program involving several of the world’s largest radio telescopes including the GBT, the Arecibo radio telescope in Puerto Rico, and ASTRON’s Westerbork Synthesis Radio Telescope in the Netherlands. West Virginia University graduate student Jason Boyles was the first to detect the millisecond pulsar, spinning nearly 366 times per second, and captured in a system which isn’t any larger than Earth’s orbit around the Sun. This close knit association, coupled with the fact the trio of stars is far denser than the Sun create the perfect conditions to examine the true nature of gravity. Generations of scientists have waited for such an opportunity to study the ‘Strong Equivalence Principle’ postulated in Einstein’s theory of General Relativity. “This triple star system gives us the best-ever cosmic laboratory for learning how such three-body systems work, and potentially for detecting problems with General Relativity, which some physicists expect to see under such extreme conditions,” says first author Scott Ransom of the National Radio Astronomy Observatory (NRAO).

“It was a monumental observing campaign,” comments Jason Hessels, of ASTRON (the Netherlands Institute for Radio Astronomy) and the University of Amsterdam. “For a time we were observing this pulsar every single day, just so we could make sense of the complicated way in which it was moving around its two companion stars.” Hessels led the frequent monitoring of the system with the Westerbork Synthesis Radio Telescope.

Not only did the research team tackle a formidable amount of data, but they also took on the challenge of modeling the system. “Our observations of this system have made some of the most accurate measurements of masses in astrophysics,” says Anne Archibald, also from ASTRON. “Some of our measurements of the relative positions of the stars in the system are accurate to hundreds of meters, even though these stars are about 10,000 trillion kilometers from Earth” she adds.

Leading the study, Archibald created the system simulation which predicts its motions. Using the solid science methods once employed by Isaac Newton to study the Earth-Moon-Sun system, she then combined the data with the ‘new’ gravity of Albert Einstein, which was necessary to make sense of the information. “Moving forward, the system gives the scientists the best opportunity yet to discover a violation of a concept called the Strong Equivalence Principle. This principle is an important aspect of the theory of General Relativity, and states that the effect of gravity on a body does not depend on the nature or internal structure of that body.”

Need a refresher on the equivalence principle? Then if you don’t remember Galileo’s dropping two different weighted balls from the Leaning Tower of Pisa, then perhaps you’ll recall Apollo 15 Commander Dave Scott’s dropping of a hammer and a falcon feather while standing on the airless surface of the Moon in 1971. Thanks to mirrors left on the lunar surface, laser ranging measurements have been studied for years and provide the strongest constraints on the validity of the equivalence principle. Here the experimental masses are the stars themselves, and their different masses and gravitational binding energies will serve to check whether they all fall towards each other according to the Strong Equivalence Principle, or not. “Using the pulsar’s clock-like signal we’ve started testing this,” Archibald explains. “We believe that our tests will be much more sensitive than any previous attempts to find a deviation from the Strong Equivalence Principle.” “We’re extremely happy to have such a powerful laboratory for studying gravity,” Hessels adds. “Similar star systems must be extremely rare in our galaxy, and we’ve luckily found one of the few!”

Original Story Source: Astronomie Netherlands News Release. Further reading: Max-Planck-Institut für Radioastronomie (MPIfR) and NRAO Press Release.

Posted on by David Dickinson

Gravitational Lens Seen for the First Time in Gamma Rays

blazar

An exciting new discovery was unveiled early this week at the 223rd  meeting of the American Astronomical Society being held in Washington D.C., when astronomers announced that a gravitational lens was detected for the first time at gamma-ray wavelengths.

The study was conducted using NASA’s Fermi Gamma Ray Space Telescope, and promises to open a new window on the universe, giving astrophysicists another tool to study the emission regions that exist near supermassive black holes.

But the hunt wasn’t easy. A gravitational lens occurs when a massive foreground object, such as a galaxy, bends the light from a distant background object. In the case of this study, researchers targeted a blazar known as B0218+357, a energetic source located 4.35 billion light years away in the direction of the constellation Triangulum.

Blazar and quasar sources are named using their respective coordinates in the sky. Think of “0218+357” as translating into “Right Ascension 2 Hours 18 Minutes, Declination +35.7 degrees north” in backyard astronomer-speak.  A blazar is a compact form of quasar that results from a supermassive black hole at the heart of an active galaxy. The term blazar was first coined by Edward Spiegel in 1978. The first quasar discovered was 3C 273 in 1970, which was also later found to be a blazar. 3C 273 is visible in Virgo using a large backyard telescope.

A foreground spiral galaxy seen face on lies along our line of sight between our vantage point and B0218+357. At 4 billion light years distant, the two have the smallest angular separation of any gravitationally lensed system so far identified at less than a third of an arc second across.

“We began thinking about the possibility of making this observation a couple of years after Fermi launch, and all of the pieces finally came together in late 2012,” said Naval Research Laboratory astrophysicist and lead scientist on the study Teddy Cheung in a recent NASA Goddard Spaceflight Center press release.

Observations of the blazar suggested that it would be flaring in September 2012, making it a prime target for the study. In fact, B0218+357 was the brightest extra-galactic gamma-ray source at the time. Cheung was granted time spanning late September into October 2012 to use Fermi’s Large Area Telescope (LAT) instrument to study the blazar in outburst.

Fermi‘s LAT instrument doesn’t have the resolution possessed by radio and optical instruments to catch the blazar in single images. Instead, the team exploited a phenomenon known as the “delayed playback effect” to catch the blazar in action.

“One light path is slightly longer than the other, so when we detect flares in one image we try and catch them days later when they replay in the other image,” Said team member Jeff Scargle, astrophysicist based at NASA’s Ames Research Center.

Cheung presented the findings of the study Monday at the American Astronomical Society meeting, which included three distinct flaring episodes from the background blazar that demonstrated the tell-tale delayed playback events with a period spanning 11.46 days.

A Hubble Space Telescope image of the gravitational lensing of B0218+357. Credit: NASA/ESA and the Hubble Legacy Archive.
A Hubble Space Telescope image of the gravitational lensing of B0218+357. Credit: NASA/ESA and the Hubble Legacy Archive.

Follow-up observations in radio and optical wavelengths supported the key observations, and demonstrate that Fermi’s LAT imager did indeed witness the event. Interestingly, the delay for the gamma-rays from the lensed blazar takes about a day longer than radio waves to reach the Earth. B0218+357 is also about four times brighter in gamma-rays than in radio wavelengths.

This occurs because the gamma-rays are emanating from a slightly different region than radio waves generated by the blazar, and are taking a different path though the gravitational field of the foreground galaxy. This demonstrates that assets like Fermi can be used to probe the heart of the distant energetic galactic nuclei which harbor supermassive black holes. This opens the hot topic of gravitationally lensed blazars and their role in extra-galactic astronomy up to the gamma-ray spectrum, and gives cosmologists another gadget for their tool box.

“Over the course of a day, one of these flares can brighten the blazar by 10 times in gamma-rays but only 10 percent in visible light and radio, which tells us that the region emitting gamma-rays is very small compared to those emitting at lower energies,” Said Stockholm University team member Stefan Larsson in the recent press release.

Using the analysis of lensing systems at gamma-ray wavelengths will not only help to probe these enigmatic cosmological beasts, but it may also assist with refining the all-important Hubble Constant, which measures the rate at which the universe is expanding.

But Fermi may just beginning to show its stuff when it comes to hunting for extra-galactic sources. The really exciting breakthrough, researchers say, would be the discovery of an energetic extra-galactic source being lensed by a foreground galaxy in gamma-rays that hasn’t been seen been seen at other wavelengths. This recent finding has certainly demonstrated how Fermi can “see” these tell-tale flashes via a clever method. Expect more news in the coming years!

Read the entire paper on the arViv server titled Fermi-LAT Detection of Gravitational Lens Delayed Gamma-ray Flares from Blazar B0218+357.

Posted on by Jason Major

ESA’s Gaia Mission Launches to Map the Milky Way

Soyuz VS06, with Gaia space observatory, lifted off from Europe's Spaceport, French Guiana, on 19 December 2013. (ESA–S. Corvaja)

Early this morning, at 09:12 UTC, the cloudy pre-dawn sky above the coastal town of Kourou, French Guiana was brilliantly sliced by the fiery exhaust of a Soyuz VS06, which ferried ESA’s “billion-star surveyor” Gaia into space to begin its five-year mission to map the Milky Way.

Ten minutes after launch, after separation of the first three stages, the Fregat upper stage ignited, successfully delivering Gaia into a temporary parking orbit at an altitude of 175 km (108 miles). A second firing of the Fregat 11 minutes later took Gaia into its transfer orbit, followed by separation from the upper stage 42 minutes after liftoff. 46 minutes later Gaia’s sunshield was deployed, and the spacecraft is now cruising towards its target orbit around L2, a gravitationally-stable point in space located 1.5 million km (932,000 miles) away in the “shadow” of the Earth.

The launch itself was really quite beautiful, due in no small part to the large puffy clouds over the launch site. Watch the video below:

A global space astrometry mission, Gaia will make the largest, most precise three-dimensional map of our galaxy by surveying more than a billion stars over a five-year period.

“Gaia promises to build on the legacy of ESA’s first star-mapping mission, Hipparcos, launched in 1989, to reveal the history of the galaxy in which we live,” says Jean-Jacques Dordain, ESA’s Director General.

Soyuz VS06, with Gaia, lifted off from French Guiana, 19 December 2013. (ESA - S. Corvaja)
Soyuz VS06 with Gaia (ESA – S. Corvaja, 2013)

Repeatedly scanning the sky, Gaia will observe each of the billion stars an average of 70 times each over the five years. (That’s 40 million observations every day!) It will measure the position and key physical properties of each star, including its brightness, temperature and chemical composition.

By taking advantage of the slight change in perspective that occurs as Gaia orbits the Sun during a year, it will measure the stars’ distances and, by watching them patiently over the whole mission, their motions across the sky.

The motions of the stars can be put into “rewind” to learn more about where they came from and how the Milky Way was assembled over billions of years from the merging of smaller galaxies, and into “fast forward” to learn more about its ultimate fate.

“Gaia represents a dream of astronomers throughout history, right back to the pioneering observations of the ancient Greek astronomer Hipparchus, who catalogued the relative positions of around a thousand stars with only naked-eye observations and simple geometry. Over 2,000 years later, Gaia will not only produce an unrivaled stellar census, but along the way has the potential to uncover new asteroids, planets and dying stars.”

– Alvaro Giménez, ESA’s Director of Science and Robotic Exploration

Gaia will make an accurate map of the stars within the Milky Way from its location at L2 (ESA/ATG medialab; background: ESO/S. Brunier)
Gaia will make an accurate map of a billion stars within the Milky Way from its location at L2 (ESA/ATG medialab; background: ESO/S. Brunier)

Of the one billion stars Gaia will observe, 99% have never had their distances measured accurately. The mission will also study 500,000 distant quasars, search for exoplanets and brown dwarfs, and will conduct tests of Einstein’s General Theory of Relativity.

“Along with tens of thousands of other celestial and planetary objects,” said ESA’s Gaia project scientist Timo Prusti, “this vast treasure trove will give us a new view of our cosmic neighbourhood and its history, allowing us to explore the fundamental properties of our Solar System and the Milky Way, and our place in the wider Universe.”

Follow the status of Gaia on the mission blog here.

Source: ESA press release and Gaia fact sheet

Gaia's launch aboard an Arianespace-operated Soyuz on Dec. 19, 2013 from ESA's facility in French Guiana (ESA)
Gaia’s launch aboard an Arianespace-operated Soyuz on Dec. 19, 2013 from ESA’s facility in French Guiana (ESA)
Posted on by Tammy Plotner

Argon – The First Noble Gas Molecules Discovered In Space

Messier 1 Hubble Image: Credit - NASA, ESA, J. Hester and A. Loll (Arizona State University)

There are only six of them: radon, helium, neon, krypton, xenon and the first molecules to be discovered in space – argon. They are all odorless, colorless, monatomic gases with very low chemical reactivity. So where did a team of astronomers using ESA’s Herschel Space Observatory make their rather unusual discovery? Try Messier 1… The “Crab” Nebula!

In a study led by Professor Mike Barlow (UCL Department of Physics & Astronomy), a UCL research team was taking measurements of cold gas and dust regions of this famous supernova remnant in infrared light when they stumbled upon the chemical signature of argon hydrogen ions. By observing in longer wavelengths of light than can be detected by the human eye, the scientists gave credence to current theories of how argon occurs naturally.

“We were doing a survey of the dust in several bright supernova remnants using Herschel, one of which was the Crab Nebula. Discovering argon hydride ions here was unexpected because you don’t expect an atom like argon, a noble gas, to form molecules, and you wouldn’t expect to find them in the harsh environment of a supernova remnant,” said Barlow.

When it comes to a star, they are hot and ignite the visible spectrum. Cold objects like nebular dust are better seen in infrared, but there’s only one problem – Earth’s atmosphere interferes with the detection of that end of the electromagnetic spectrum. Even though we can see nebulae in visible light, what shows is the product of hot, excited gases, not the cold and dusty regions. These invisible regions are the specialty of Herschel’s SPIRE instruments. They map the dust in far-infrared with their spectroscopic observations. In this instance, the researchers were somewhat astounded when they found some very unusual data which required time to fully understand.

“Looking at infrared spectra is useful as it gives us the signatures of molecules, in particular their rotational signatures,” Barlow said. “Where you have, for instance, two atoms joined together, they rotate around their shared center of mass. The speed at which they can spin comes out at very specific, quantized, frequencies, which we can detect in the form of infrared light with our telescope.”

According to the news release, elements can exist in varying forms known as isotopes. These have different numbers of neutrons in the atomic nuclei. When it comes to properties, isotopes can be somewhat alike to each other, but they have different masses. Because of this, the rotational speed is dependent on which isotopes are present in a molecule. “The light coming from certain regions of the Crab Nebula showed extremely strong and unexplained peaks in intensity around 618 gigahertz and 1235 GHz.” By comparing data of known properties of different molecules, the science team came to the conclusion the mystery emission was the product of spinning molecular ions of argon hydride. What’s more, it could be isolated. The only argon isotope which could spin like that was argon-36! It would appear the energy released from the central neutron star in the Crab Nebula ionized the argon, which then combined with hydrogen molecules to form the molecular ion ArH+.

Professor Bruce Swinyard (UCL Department of Physics & Astronomy and Rutherford Appleton Laboratory), a member of the team, added: “Our discovery was unexpected in another way — because normally when you find a new molecule in space, its signature is weak and you have to work hard to find it. In this case it just jumped out of our spectra.”

Is this instance of argon-36 in a supernova remnant natural? You bet. Even though the discovery was the first of its kind, it is doubtless not the last time it will be detected. Now astronomers can solidify their theories of how argon forms. Current predictions allow for argon-36 and no argon-40 to also be part of supernova structure. However, here on Earth, argon-40 is a dominant isotope, one which is created through the radioactive decay of potassium in rocks.

Noble gas research will continue to be a focus of scientists at UCL. As an amazing coincidence, argon, along with other noble gases, was discovered at UCL by William Ramsay at the end of the 19th century! I wonder what he would have thought had he known just how very far those discoveries would take us?

Original Story Source: University College London (UCL) Press Release

Posted on by Tammy Plotner

Mapping Molecular Clouds Changes Astronomers Outlook On Starbirth

Molecular hydrogen in the Whirlpool Galaxy M51. The blueish features show the distribution of hydrogen molecules in M51, the raw material for forming new stars. The PAWS team has used this data to create a catalogue of more then 1,500 molecular clouds. The background is a color image of M51 by the Hubble Space Telescope. Superimposed in blue is the CO(1-0) radiation emitted by carbon monoxide (CO) molecules, as measured for the PAWS study using the millimeter telescopes of the Institut de Radioastronomie Millimétrique. The CO molecules are used as tracers for molecular hydrogen. Credit: PAWS team/IRAM/NASA HST/T. A. Rector (University of Alaska Anchorage)

It didn’t happen overnight. By studying the properties of giant molecular clouds in the Whirlpool Galaxy for several years with the millimeter telescopes of IRAM, the Institut de Radioastronomie Millimétrique, astronomers have been given a whole, new look at star formation. Encompassing 1,500 maps of molecular clouds, this new research has found these building blocks of future suns to be encased in a sort of molecular hydrogen mist. This ethereal mixture appears to be far denser than speculated and is found throughout the galactic disc. What’s more, it would appear the pressure created by the molecular fog is a critical factor in determining whether or not stars are able to form within the clouds.

Stars form in the molecular clouds housed within all galaxies. These formations are vast areas of hydrogen molecules with masses which total from a thousand to several million times that of the Sun. When an area of the cloud folds under the weight of its own gravity, it collapses. Pressure and temperature rise and nuclear fusion begins. A star is born.

This exciting new research is changing the way astronomers think about starbirth regions. Study leader Eva Schinnerer (Max Planck Institute for Astronomy) explains: “Over the past four years, we have created the most complete map yet of giant molecular clouds in another spiral galaxy similar to our own Milky Way, reconstructing the amounts of hydrogen molecules and correlating them with the presence of new or older stars. The picture that is emerging is quite different from what astronomers thought these clouds should be like.” The survey, known as PAWS, targeted the Whirlpool galaxy, also known as M51, at a distance of about 23 million light-years in the constellation Canes Venatici – the Hunting Dogs.

Annie Hughes, a post-doctoral researcher at MPIA involved in the study, says: “We used to think of giant molecular clouds as solitary objects, drifting within the surrounding interstellar medium of rarified gas in isolated splendor; the main repository of a galaxy’s supply of hydrogen molecules. But our study shows that 50% of the hydrogen is outside the clouds, in a diffuse, disk-shaped hydrogen fog permeating the galaxy!”

Not only does the enveloping gas play a critical part in star formation, but galaxy structure does as well. One galactic feature in particular is key – spiral arm structure. They sweep slowly around the core area like hands on a clock and are more populated with stars than the remainder of the galactic disk. Sharon Meidt, another MPIA post-doctoral researcher involved in the study, says: “These clouds are definitely not isolated. On the contrary, interactions between clouds, fog, and overall galactic structure appear to hold the key to whether or not a cloud will form new stars. When the molecular fog moves relative to the galaxy’s spiral arms, the pressure it exerts on any clouds within is reduced, in line with a physical law known as Bernoulli’s principle. Clouds feeling this reduced pressure are unlikely to form new stars. According to the press release, Bernoulli’s law is also thought to be responsible for part of the well-known shower-curtain effect: shower curtains blowing inward when one takes a hot shower, another display of reduced pressure.

Jerome Pety of the Institut de Radioastronomie Millimétrique (IRAM), which operates the telescopes used for the new observations, says: “It’s good to see our telescopes live up to their full potential. A study that needed such extensive observation time, and required both an interferometer to discern vital details and our 30 m antenna to put those details into a larger context, would not have been possible at any other observatory.”

Schinnerer concludes: “So far, the Whirlpool galaxy is one example which we have studied in depth. Next, we need to check that what we have found also applies to other galaxies. For our next steps, we hope to profit from both the extension NOEMA of the compound telescope on the Plateau de Bure and from the newly opened compound telescope ALMA in Chile, which will allow in-depth studies of more distant spiral galaxies.”

Original Story Source: Max Planck Institute for Astronomy News Release.

Posted on by Tammy Plotner

Subaru Telescope Reveals Orderly Massive Galaxy Evolution

FMOS spectra in the J-band (left panel) and H-band (right panel), each of which filters light so that only specific wavelengths can pass through. The horizontal axis refers to the wavelength direction while the vertical axis indicates individual spectra observed through each fiber. Small blue circles indicate the detection of emission lines (left: H? and [OIII]; right: H?, [NII]). The inset box shows the intensity of the emission lines for one galaxy. The vertical bands indicate the masked regions where bright sky (OH) emissions are prevented from entering science fibers placed on high-redshift galaxies. (Credit: FMOS-COSMOS)

Nobody likes a sloppy COSMOS (Cosmological Evolution Survey) and astronomers utilizing the Fiber-Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope have put order into chaos through their studies. The survey has found that some nine billion years ago galaxies were capable of producing new stars in a fashion as orderly as game of checkers. Despite their young cosmological age, the galaxies show signs containing high amounts of dust enriched by heavier elements – a mature state.

“These findings center on a major question: What was the universe like when it was maximally forming its stars?” says John Silverman, the principal investigator of the FMOS-COSMOS project at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU).

These “universal” questions are just what the COSMOS team seeks to answer. Their research goals are to enlighten the scales of cosmic time in relationship with the environment, formation and evolution of massive galactic structures. When studying individual galaxies, they may be able to tell if their rate of growth can be attributed to large-scale environments. Information of this type can clarify what factors the early Universe structure may have contributed to the current form of local galaxies. One of the data sets the team is focusing on is using the FMOS on the Subaru Telescope to chart out the distribution of more than a thousand galaxies which formed over nine billion years ago – a time when the Universe was hitting its star-formation peak.

“One key to generating fruitful results is collaboration between COSMOS researchers to maximize optimal use of FMOS.” Silverman continues, “In this project, researchers from Kavli IPMU in Japan and the Institute for Astronomy at the University of Hawaii (principal investigator: David Sanders) formed an effective collaboration to implement their goal.” The observations spanned 10 clear nights starting in March 2012.

Why choose spectroscopy? This advanced fiber optics technology speaks for itself, collecting light over an area of sky equal in size to that of the Moon. The FMOS focuses on the near-infrared, filtering out unwanted emissions caused by warm temperatures and can acquire spectra from 400 galaxies simultaneously with a wide field of coverage of 30 arc minutes at prime-focus. By employing such a wide field of view, astronomers can squeeze in a wide range of objects in their local environments. This enables researchers to maximize information on star-forming regions, cluster formation, and cosmology.

As David Sanders, the principal investigator of the FMOS-COSMOS project at IfA, puts it, “FMOS has clearly revolutionized our ability to study how galaxies form and evolve across cosmic time. It is currently the most powerful instrument we have to study the large numbers of objects needed to understand galaxies of all sizes, shapes and masses — from the largest ellipticals to the smallest dwarfs. We are extremely fortunate that the Kavli IPMU-IfA collaboration is giving us this unique opportunity to study the distant universe in such exquisite detail.”

FMOS will soon be famous by revealing its true potential. It has been collecting copious amounts of data in a high spectral resolution mode and at a very successful rate. So far it has accomplished nearly half of its goal – to examine over a thousand galaxies with redshifts to map the large-scale structure. The current survey consists of mapping an area of sky which spans a square degree in high-resolution mode and future plans for FMOS will involve enlarging the area. This expanded coverage will complement other instruments on alternative telescopes which have a wider spectral imaging system or a higher resolution which is limited to a smaller area. These combined findings may one day result in showing us some of the very first structures that eventually evolved into the massive galaxy clusters we see today!

Original Story Source: Kavli Institute for the Physics and Mathematics of the Universe News Release.

Posted on by Tammy Plotner

Forging Stars – Peering Into Starbirth and Death

The Large Magellanic Cloud is one of the closest galaxies to our own. Astronomers have now used the power of the ESO’s Very Large Telescope to explore NGC 2035, one of its lesser known regions, in great detail. This new image shows clouds of gas and dust where hot new stars are being born and are sculpting their surroundings into odd shapes. But the image also shows the effects of stellar death — filaments created by a supernova explosion (left). Credit: ESO

Some 160,000 light years away towards the constellation of Dorado (the Swordfish), is an amazing area of starbirth and death. Located in our celestial neighbor, the Large Magellanic Cloud, this huge stellar forge sculpts vast clouds of gas and dust into hot, new stars and carves out ribbons and curls of nebulae. However, in this image taken by ESO’s Very Large Telescope, there’s more. Stellar annihilation also awaits and shows itself as bright fibers left over from a supernova event.

For southern hemisphere observers, one of our nearest galactic neighbors, the Large Magellanic Cloud, is a well-known sight and holds many cosmic wonders. While the image highlights just a very small region, try to grasp the sheer size of what you are looking at. The fiery forge you see is several hundred light years across, and the factory in which it is contained spans 14,000 light years. Enormous? Yes. But compared to the Milky Way, it’s ten times smaller.

Even at such a great distance, the human eye can see many bright regions where new stars are actively forming, such as the Tarantula Nebula. This new image, taken by ESO’s Very Large Telescope at the Paranal Observatory in Chile, explores an area cataloged as NGC 2035 (right), sometimes nicknamed the Dragon’s Head Nebula. But, just what are we looking at?

The Dragon’s Head is an HII region, more commonly referred to as an emission nebula. Here, young stars pour forth energetic radiation and illuminate the surrounding clouds. The radiation tears electrons away from the atoms contained within the gas. These atoms then gel again with other atoms and release light. Swirling in the mix is dark dust, which absorbs the light and creates deep shadows and create contrast in the nebula’s structure.

However, as we look deep into this image, there’s even more… a fiery finale. At the left of the photo you’ll see the results of one of the most violent events in the Universe – a supernova explosion. These troubled tendrils are all that’s left of what once was a star and its name is SNR 0536-67.6. Perhaps when it exploded, it was so bright that it was capable of outshining the Magellanic Cloud… fading away over the weeks or months that followed. However, it left a lasting impression!

Original Story Source: ESO Image Release.

Posted on by Elizabeth Howell

Anybody Want A Peanut? New Model Shows Tasty Orbital Shapes In Milky Way’s Bulge

Artist's impression of the Milky Way, looking at it edge on. This makes the bulge at the center look like a peanut, astronomers say. Credit: ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt.

Remember that 3-D map of the Milky Way that postulated that the center of the galaxy is shaped like a box or peanut? A new math model of the bulge shows that stars in the center of that bulge move in figure-eight orbits (which can also be interpreted as a peanut-shell shape.) Before, previous studies suggested these orbits looked more like bananas.

“The difference is important; astronomers develop theories of star motions to not only understand how the stars in our galaxy are moving today but also how our galaxy formed and evolves,” the Royal Astronomical Society stated.

In the middle of the galaxy, there are a lot of gravitational forces at play due to the sheer number of stars, as well as particles of dust and dark matter, congregating in the area. This makes it harder to model orbits than in more simple situations, such as our own solar system.

This is how a new model envisions it working:

Milky Way. Image credit: NASA
Milky Way. Image credit: NASA

“As the stars go round in their orbits, they also move above or below the plane of the bar. When stars cross the plane they get a little push, like a child on a swing,” the RAS said.

“At the resonance point, which is a point a certain distance from the center of the bar, the timing of the pushes on the stars is such that this effect is strong enough to make the stars at this point move up higher above the plane. (It is like when a child on the swing has been pushed a little every time and eventually is swinging higher.) These stars are pushed out from the edge of the bulge.”

The researchers suppose that the stars would have two “vertical oscillations” in each orbit, but in between the orbits are shaped somewhat like a peanut shell. This “could give rise to the observed shape of the bulge, which is also like a peanut-shell,” RAS stated.

The research (led by Alice Quillen, an astronomy researcher at the University of Rochester) is available in the Monthly Notices of the Royal Astronomical Society, as well as (in preprint version) on Arxiv.

Source: Royal Astronomical Society

Posted on by Jason Major

Astronomers Catch a Galactic Threesome in the Act

A combined image from the Spitzer, Hubble, and Subaru telescopes show this structure to be three galaxies merging into one (NASA/JPL-Caltech/STScI/NAOJ/Subaru)

An enormous and incredibly luminous distant galaxy has turned out to actually be three galaxies in the process of merging together, based on the latest observations from ALMA as well as the Hubble and Spitzer space telescopes. Located 13 billion light-years away, this galactic threesome is being seen near the very beginning of what astronomers call the “Cosmic Dawn,” a time when the Universe first became illuminated by stars.

“This exceedingly rare triple system, seen when the Universe was only 800 million years old, provides important insights into the earliest stages of galaxy formation during a period known as ‘Cosmic Dawn’ when the Universe was first bathed in starlight,” said Richard Ellis, professor of astronomy at Caltech and member of the research team. “Even more interesting, these galaxies appear poised to merge into a single massive galaxy, which could eventually evolve into something akin to the Milky Way.”

In the image above, infrared data from NASA’s Spitzer Space Telescope are shown in red, visible data from NASA’s Hubble Space Telescope are green, and ultraviolet data from Japan’s Subaru telescope are blue. First discovered in 2009, the object is named “Himiko” after a legendary queen of Japan.

The merging galaxies within Himiko are surrounded by a vast cloud of hydrogen and helium, glowing brightly from the galaxies’ powerful outpouring of energy.

What’s particularly intriguing to astronomers is the noted lack of heavier elements like carbon in the cloud.

“This suggests that the gas cloud around the galaxy is actually quite primitive in its composition,” Ellis states in an NRAO video, “and has not yet been enriched by the products of nuclear fusion in the stars in the triple galaxy system. And what this implies is that the system is much younger and potentially what we call primeval… a first-generation object that is being seen. If true that’s very very exciting.”

Further research of distant objects like Himiko with the new high-resolution capabilities of ALMA will help astronomers determine how the Universe’s first galaxies “turned on”… was it a relatively sudden event, or did it occur gradually over many millions of years?

Watch the full video from the National Radio Astronomy Observatory below:

The research team’s results have been accepted for publication in the Astrophysical Journal.

Source: NASA/JPL press release and the NRAO.

Posted on by Elizabeth Howell

‘Elephant Trunks’ Crowd Distant Star Cluster, Raising New Questions About Stellar Formation

NGC 3572 seen with a 2.2-meter telescope at the European Southern Observatory's La Silla Observatory in Chile. Credit: ESO/G. Beccari

Star winds are pushing the gas around NGC 3572 into “elephant trunks”, as you can see if you look carefully as this picture snapped by a La Silla Observatory telescope at the European Southern Observatory in Chile. It’s a demonstration of the power of the youngster blue-white stars embedded in the cloud, which are generating huge gusts blowing the gas and dust away from them.

It’s common for young stars to form in groups. After a few million years growing together, their respective gravities pushes everything further apart, and the stars then finish their lifetimes on their own. Looking at young star clusters such as this gives astronomers a better sense about how our own Sun began its life.

If we zoomed closer to those elephant trunks, they would look similar to the famous “Pillars of Creation” image captured in 1995 by the Hubble Space Telescope in the Eagle Nebula (M16). NASA also did a follow-up observation using infrared wavelengths in 2005 and 2011, which made the young stars a bit easier to see amid the gas and dust.

One of the Hubble Space Telescope's most famous images, the "Pillars of Creation" in the Eagle Nebula. Credit: NASA/ESA
One of the Hubble Space Telescope’s most famous images, the “Pillars of Creation” in the Eagle Nebula. Credit: NASA/ESA

As for the picture of NGC 3572, the high-resolution image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope is also revealing new mysteries that will require further investigation, ESO stated.

“A strange feature captured in this image is the tiny ring-like nebula located slightly above the centre of the image,” ESO wrote. “Astronomers still are a little uncertain about the origin of this curious feature. It is probably a dense leftover from the molecular cloud that formed the cluster, perhaps a bubble created around a very bright hot star. But some authors have considered that it may be some kind of oddly shaped planetary nebula — the remnants of a dying star.”

Astronomers were also surprised by seeing stars older than 10 million years old within this image that were still picking up mass, which implies that planetary formation could take longer than previously believed.

Research was led by ESO astronomer Giacomo Beccari.

Source: European Southern Observatory