This broad panorama of the Carina Nebula, a region of massive star formation in the southern skies, was taken in infrared light using the HAWK-I camera on ESO’s Very Large Telescope. Many previously hidden features, scattered across a spectacular celestial landscape of gas, dust and young stars, have emerged.

View larger image here.

(image: European Southern Observatory, T. Priebisch)

(Source: rhamphotheca)

At the edges of the visible universe, 45 billion light-years away, sit some of the oldest known galaxies. How they formed and developed is a mystery, but a spectrograph installed on Chile’s Very Large Telescope—functional since March—should help astronomers find answers. The six-foot-wide, three-ton instrument contains 24 motorized robotic arms. Each eight-inch arm controls a mirror that focuses on a single galaxy. As a result, the telescope can collect infrared readings for 24 galaxies at the same time—data that show what they looked like when the universe was only a fraction of its current age. With the simultaneous observations, astronomers can perform faster and more precise statistical comparisons between galaxies than with isolated viewings.

photo: Armed Telescope. credit: STFC/UKATC/ESO
source: popsci

Super-Fast New Telescope Solves Star Birth Mystery

ALMA is the best way to see these births in super-fertile galaxies, which helps scientists understand how galaxies form.

image: ALMA Galaxies. This image shows six of the most fertile galaxies in the early universe as seen by ALMA (in red). The red circles indicate the regions where galaxies had been detected by a less-sensitive telescope setup called APEX. The earlier telescope did not have sharp enough images to pin down the identity of the galaxies, but ALMA does.
The ALMA observations, at submillimeter wavelengths, are overlaid on an infrared view of the region as seen by the Spitzer Space Telescope (blue). ALMA (ESO/NAOJ/NRAO), APEX (MPIfR/ESO/OSO), J. Hodge et al., A. Weiss et al., NASA Spitzer Science Center

Birth is messy, for stars as for anything else, and it can be hard for astronomers to see through the dirt and crud. This is especially true in distant, very old galaxies, which also happen to be some of the most fertile galaxies. To better understand how stars in these galaxies are born, astronomers need to see through the dust surrounding them—the interstellar afterbirth, if you will. This takes a telescope that can see long wavelengths of light, around one millimeter. It takes a telescope with some soul.

The newly christened Atacama Large Millimeter/submillimeter Array can do it better and faster than any observatory to come before it. This week, astronomers report using ALMA for just a few hours, and making new sensitive observations of these star-forming regions in the early universe. ALMA is so powerful that it did in a few hours what it took other telescopes decades to achieve.

“ALMA is so powerful that it has revolutionized the way that we can observe these galaxies, even though the telescope was not fully completed at the time of the observations,” said lead study author Jacqueline Hodge of the Max Planck Institute for Astronomy in Germany, in a statement.

Prior to ALMA’s observations, the best map of these galaxies was with an ALMA precursor, the Atacama Pathfinder Experiment (APEX). Perched at the ALMA site 16,400 feet above sea level in the Chilean Andes, APEX’s 12-meter dish surveyed a piece of sky in the southern constellation of Fornax (the Furnace) about as big as the full moon. It found 126 galaxies, but they were fuzzy blobs, and so not very useful to study. ALMA is an array of 66 of these dishes (16 of those are slightly smaller), making it much more sensitive.

ALMA was able to spot the same galaxies within two minutes each, pinpointing them in a region 200 times smaller than the APEX blobs and at triple the sensitivity. Put another way, ALMA doubled the total number of these observations ever made—spread over more than a decade—in a couple hours, and with unmatched precision.

The main reason this is helpful: ALMA was able to tease out the blobs and identify numerous galaxies, where in other observations, what looked like a single blob was actually numerous objects. This makes astronomers more comfortable, because it means the blobs were not birthing ludicrous amounts of stars, which would have made them unstable. “The ALMA images revealed multiple, smaller galaxies forming stars at somewhat more reasonable rates,” said Alexander Karim of Durham University in the UK.

Stay Curious! Learn more about ALMA.

This space wallpaper shows an artist’s impression of the surface of the distant dwarf planet Makemake. This dwarf planet is about two thirds of the size of Pluto, and travels around the Sun in a distant path that lies beyond that of Pluto, but closer to the Sun than Eris, the most massive known dwarf planet in the Solar System. Makemake was expected to have an atmosphere like Pluto, but this has now been shown to not be the case.

credit: ESO/L. Calçada/Nick Risinger (skysurvey.org)

skeptv:

Seagull Nebula’s Wings Set Aflame by Ultraviolet Radiation

The fires of star birth light up the nebula’s hydrogen gas bright red. Europe’s MPG/ESO 2.2-metre telescope captured this grand view of the cosmic fowl located at along the border of Canis Major and Monoceros constellations.

by Video From Space.

electricspacekoolaid:

An Infinity of Dwarfs - A Visible Universe of 7 Trillion Dwarf Galaxies

Astronomers estimate that there are between 100 billion and 200 billion galaxies in the known universe. A single galaxy such as the Milky Way contain upwards of 200 billion normal stars. About 75 percent of of all stars in the Milky Way are less than half as massive as our Sun. In the universe at large, the majority of galaxies are classified as dwarfs, each with less than a few hundred million stars. The image above is a computer simulation of a colliding dwarf galaxy triggering the formation of the Milky Ways spiral arms.

The largest project ever undertaken to map out the Universe in three dimensions using ESO telescopes has reached the halfway stage. An international team of astronomers has used the VIMOS instrument on the ESO Very Large Telescope to measure the distances to 55 000 galaxies as part of the VIPERS survey (VIMOS Public Extragalactic Redshift Survey). This has already allowed them to create a remarkable three-dimensional view of how galaxies were distributed in space in the younger Universe.

This reveals the complex web of the large-scale structure of the Universe in great detail. The light of each galaxy is spread out into its component colours within VIMOS. Follow up analysis then allows astronomers to work out how fast the galaxy appears to move away from us — its redshift. This in turn reveals its distance and, when combined with its position on the sky, its location in the Universe.

By studying the cosmic web astronomers can test theories of how the Universe formed and evolved and help to track down the properties of the mysterious dark energy that is making the expansion of the Universe speed up. By mapping how large-scale structure grows with time they can also check whether Einstein’s theory of general relativity holds precisely, or whether it may need to be revised.

VIPERS is the most detailed survey so far of galaxies that are seen from the time when astronomers think that the Universe became dominated by dark energy, as it is today. This happened when the Universe was between about five and nine billion years old — about half its current age of 13.7 billion years. Although it is not yet complete, VIPERS is already delivering exciting science results, including both a first estimate of the growth rate of large-scale structure at this time and the best census ever of the average number of massive galaxies during this period of the Universe’s history.

ESA astronomers say that for every ten far galaxies observed, a hundred go undetected. The European Space Agency’s Herschel space telescope has discovered that previously unseen distant galaxies are responsible for a cosmic fog of infrared radiation. The galaxies are some of the faintest and furthest objects seen by Herschel, and open a new window on the birth of stars in the early Universe. Astronomers estimate that there are billions and billions of galaxies in the observable universe as well as some seven trillion dwarf galaxies.

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electricspacekoolaid:

“The Big Bang Star” - One of The First in the Universe 

A primordial star at the outer edges of our Milky Way galaxy upsets current theories of star formation in the universe. The star simply shouldn’t exist since it lacks the materials astronomers have long thought necessary for low-mass stars to form, scientists say. 

When Lorenzo Monaco of the European Southern Observatory in Chile and colleagues examined the elemental composition of the oddball star, prosaically named SDSS J102915+172927 (image below), they discovered that it has a mass smaller than that of the Sun, and is probably more than 13 billion years old.

“This star has the composition that is the nearest that has been found up to now to the big bang composition,” says Piercarlo Bonifacio of the Paris Observatory, France.

The low concentration of chemical elements heavier than hydrogen and helium suggests it is the most primitive star ever discovered, yet the exact ratio of these heavier elements suggests it is younger. Much, much younger.

“In some sense it is a perfectly normal star, but it is different because it’s in a very low metal range,” Monaco says. The relationship between a star’s age and its elemental composition stems from the way the early universe evolved.

The first stars are thought to have condensed out of the hot soup left over from the big bang and contained only hydrogen, helium and a trace of lithium. Most were giants tens of times more massive than the sun, that quickly exploded as supernovas spewing elements from carbon to iron, which subsequent generations of stars incorporated. The process occurred again and again, with younger generations of smaller stars acquiring larger fractions of heavier elements. Which is how our Sun eventually formed.

Until now, the universe seemed to agree. Astronomers had found only three stars with very low amounts of heavier elements. They were low-mass, and oxygen and carbon dominated the traces of heavier elements, which meant they passed the carbon-oxygen threshold needed to form a low-mass star – despite having a very low concentration of heavier elements overall.

But SDSS J102915+172927 is different and a mystery: it’s composed almost entirely hydrogen and helium, making it look like one of the very first in the universe. When Monaco and colleagues used two spectrographs at the Very Large Telescope in Chile to examined its elemental composition, they found it had the lowest content of heavier elements ever seen yet – 4.5 millionths that of the sun.

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n-a-s-a:

Wide-field view of the sky around VFTS 102: the fastest rotating massive star

Credit: ESO 

distant-traveller:

ALMA inauguration heralds new era of discovery

Today, in a remote part of the Chilean Andes, the Atacama Large Millimeter/submillimeter Array (ALMA), was inaugurated at an official ceremony. This event marks the completion of all the major systems of the giant telescope and the formal transition from a construction project to a fully fledged observatory.

The President of Chile, Sebastián Piñera, said: “One of our many natural resources is Chile’s spectacular night sky. I believe that science has been a vital contributor to the development of Chile in recent years. I am very proud of our international collaborations in astronomy, of which ALMA is the latest, and biggest outcome.”

Thijs de Graauw, expressed his expectations for ALMA. “Thanks to the efforts and countless hours of work by scientists and technicians in the ALMA community around the world, ALMA has already shown that it’s the most advanced millimetre/submillimetre telescope in existence, dwarfing anything else we had before. We are eager for astronomers to exploit the full power of this amazing tool.”

Tomorrow, a selected group of guests will have the opportunity to visit the telescope at the Array Operations Site, located 5000 metres above sea level. The assembly of ALMA’s antennas was recently completed, with the last batch of seven out of the final total of 66 antennas currently being tested before entering into service. The telescope has already provided unprecedented views of the cosmos with only a portion of its full array.

Able to observe the Universe by detecting light that is invisible to the human eye, ALMA will show us never-before-seen details about the birth of stars, infant galaxies in the early Universe, and planets coalescing around distant suns. It also will discover and measure the distribution of molecules — many essential for life — that form in the space between the stars.

The antennas of the ALMA array, fifty-four 12-metre and twelve smaller 7-metre dish antennas, work together as a single telescope. Each antenna collects radiation coming from space and focuses it onto a receiver. The signals from the antennas are then brought together and processed by a specialised supercomputer: the ALMA correlator. The 66 ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 metres to 16 kilometres.

Image credit: Clem & Adri Bacri-Normier (wingsforscience.com)/ESO

spaceplasma:

ALMA Rewrites History of Universe’s Stellar Baby Boom

Observations with the Atacama Large Millimeter/submillimeter Array (ALMA) show that the most vigorous bursts of star birth in the cosmos took place much earlier than previously thought. The results are published in a set of papers to appear in the journal Nature on 14 March 2013, and in the Astrophysical Journal. The research is the most recent example of the discoveries coming from the new international ALMA observatory, which celebrates its inauguration today.

The most intense bursts of star birth are thought to have occurred in the early Universe, in massive, bright galaxies. These starburst galaxies convert vast reservoirs of cosmic gas and dust into new stars at a furious pace — many hundreds of times faster than in stately spiral galaxies like our own galaxy, the Milky Way. By looking far into space, at galaxies so distant that their light has taken many billions of years to reach us, astronomers can observe this busy period in the Universe’s youth.

The international team of researchers first discovered these distant and enigmatic starburst galaxies with the US National Science Foundation’s 10-metre South Pole Telescope (SPT) and then used ALMA to zoom in on them to explore the stellar baby boom in the young Universe. They were surprised to find that many of these distant dusty star-forming galaxies are even further away than expected. This means that, on average, their bursts of star birth took place 12 billion years ago, when the Universe was just under 2 billion years old — a full billion years earlier than previously thought.

Two of these galaxies are the most distant of their kind ever seen — so distant that their light began its journey when the Universe was only one billion years old. What’s more, in one of these record-breakers, water is among the molecules detected, marking the most distant observations of water in the cosmos published to date.

The team used the unrivalled sensitivity of ALMA to capture light from 26 of these galaxies at wavelengths of around three millimetres. Light at certain specific wavelengths can be produced by gas molecules in these galaxies, and the wavelengths are stretched by the expansion of the Universe over the billions of years that it takes the light to reach us. By measuring the stretched wavelengths, astronomers can calculate how long the light’s journey has taken, and place each galaxy at the right point in cosmic history.

For more: ESO.org

Credit: ESO/ALMA

ALMA Telescope Inaugurated As 50th Antenna Goes Live

On 13 March the Atacama Large Millimeter/submillimeter Array (Alma), the largest astronomical project to grace the face of the planet, was inaugurated, celebrating its transition from a construction project to a fully-fledged observatory.

The $1.3 billion (£870 million) observatory, based in the arid Chilean desert high up on the Chajnantor plateau at an altitude of 5,000 metres, will use its 66 high-precision antennas to look for light being emitted by some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves, and is thus known as millimetre and submillimetre radiation. A total of 50 of those antenna are now functioning.

Thijs de Graauw, the director of Alma, has stated that his team is not sure when the whole project will be complete. “We’re celebrating that we have 50 antennae in operation. We took that number because to have all 66 finished could take a little bit longer, because you know the end of the project is very hard to sharply plan and define.”

Once complete, the 66 antennas range in diameter from seven to 12 metres, and will be moved across the Chajnantor plateau to cover a region up to 16 square kilometres. The Alma’s correlator — a specially designed supercomputer that acts as the array’s brain — combines the signals collected by the antennas, resulting in a final image comparable to those that would be obtained by a hypothetical giant antenna with a 14,000 metre diameter. In order for the system to work to its full potential, all 66 of the antennas and their electronics must work in perfect synchrony, with a precision of one millionth of a millionth of a second. Signals from the antenna might have to travel through 15km of fibre before they reach the correlator, where they must be assembled in a manner that matches the precise path the signal took from each antenna with an accuracy of a hundredth of a millimetre.

The lofty perch in the immensely arid Atacama Desert provides the Alma with one of the most ideal climates on Earth to collect light signals from space. As soon as a signal enters the Earth’s atmosphere it is partially absorbed and delayed by CO2, Oxygen and water vapour. Even in the dry, thin atmosphere of the Atacama, Alma has seven specially-built Water Vapour Radiometers to measure the amount of line-of-sight water vapour present in the atmosphere, and will correct for these atmospheric effects.

Astronomers and scientists (who have already used the partially completed array to search for planet-forming dust), will now be able to collect even more accurate images of cold dust that surrounds young stars, allowing them to form a better understanding of how planets form.

image: ALMA (ESO/NAOJ/NRAO), C. Padilla

(Source: spaceplasma)

Distance to Milky Way’s Neighbor Galaxy Refined

The distance to one of the Milky Way’s next-door neighbors, a satellite galaxy that orbits its outskirts, has been determined more accurately than ever before, astronomers announced today (March 6).

The achievement could help scientists calibrate other cosmic distances, which are essential for understanding how quickly the universe is expanding and solving the mystery of dark energy. Dark energy is the name given to whatever is tugging the universe apart and causing its expansion to accelerate.

According to the new measurement, the nearby dwarf galaxy called the Large Magellanic Cloud lies 163,000 light-years away.

“I am very excited because astronomers have been trying for a hundred years to accurately measure the distance to the Large Magellanic Cloud, and it has proved to be extremely difficult,” Wolfgang Gieren, an astronomer at Chile’s Universidad de Concepción, Chile, said in a statement. “Now we have solved this problem by demonstrably having a result accurate to 2 percent.”

The finding was nearly a decade in the making, and required repeated precise measurements of rare pairs of binary stars that are oriented so that they eclipse each other as they orbit, from the perspective of Earth.

Using telescopes at the European Southern Observatory’s La Silla Observatory and the Las Campanas Observatory, both in Chile, Gieren and his colleagues identified eight pairs of eclipsing binaries in the Large Magellanic Cloud.

By tracking the changes in the star pairs’ brightness when one star passed in front of the other, and vice versa, as well as measuring the stars’ orbital speeds, the scientists could deduce the stars’ sizes and masses, as well as details regarding their orbits. With this information, combined with measurements of the stars’ total brightness and colors, their precise distances could be determined.

These measurements improve on previous estimates of the Large Magellanic Cloud’s distance, which were all based on methods that had inherent uncertainties.

“Because the LMC is close and contains a significant number of different stellar distance indicators, hundreds of distance measurements using it have been recorded over the years,” said team member Ian Thompson of the Carnegie Institution for Science in Washington, D.C. “Unfortunately, nearly all the determinations have systemic errors, with each method carrying its own uncertainties.”

Pinning down the distance of the LMC, in turn, allows scientists to refine their estimates of other, farther cosmic distances. That’s because the measurements of close distances are used to calibrate measurements of far-off objects. The new findings should help astronomers narrow down the Hubble Constant, which denotes the rate of the universe’s expansion, and is integral for the study of dark energy.

“We are working to improve our method still further and hope to have a 1 percent LMC distance in a very few years from now,” said researcher Dariusz Graczyk . “This has far-reaching consequences not only for cosmology, but for many fields of astrophysics.”

The findings are detailed in the March 8 issue of the journal Nature.

image: This illustration shows an eclipsing binary star system. As the two stars orbit each other they pass in front of one another and their combined brightness, seen from a distance, decreases. By studying how the light changes, and other properties of the system, astronomers can measure the distances to eclipsing binaries very accurately.
CREDIT: ESO/L. Calçada

Watch: Eclipsing Stars’ Light Shift Quantifies Distance To Earth

n-a-s-a:

Collision Between Galaxies (Artist’s Impression)

The new results obtained with GIRAFFE on the VLT seem to show that collisions and merging are important in the formation and evolution of galaxies. Here, such a collision is shown in this artist’s impression.

Credit: ESO 

distant-traveller:

Star clusters surround galaxy ESO 243-49

This spectacular edge-on galaxy, called ESO 243-49, is home to an intermediate-mass black hole that may have been purloined from a cannibalised dwarf galaxy. The black hole, with an estimated mass of 50 million Suns, lies above the galactic plane. This is an unlikely place for such a massive back hole to exist, unless it belonged to a small galaxy that was gravitationally torn apart by ESO 243-49.

Image credit: NASA, ESA, and S. Farrell (University of Sydney, Australia and University of Leicester, UK)