ESO ALMA: The first interferometric image at 500 GHz with ALMA Band 8 receivers

Planetary Nebula NGC 6302. The right image is the composite image of ALMA Band 8 (yellow) and the Hubble Space Telescope (gray). 

Upper left image is the whole view of NGC 6302 taken by the Hubble Space Telescope, and yellow rectangle corresponds to the right image area. Lower left panel shows the line profile of atomic carbon. 

Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope

ALMA opens another window to the universe in the 500 GHz frequency band. Astronomers successfully synthesized the distribution of atomic carbon around a planetary nebula NGC 6302 in test observations with the ALMA Band 8 receiver, developed by the National Astronomical Observatory of Japan (NAOJ).

This is the first 500 GHz band astronomical image captured by a radio interferometer with unprecedentedly high resolution.

ALMA has 10 receiver bands to cover a wide range of observing frequency. All antennas are equipped with dedicated receivers for each frequency band.

NAOJ assumes the development of three bands: Band 4 (receiving frequency: 125 to 163 GHz, millimeter-wave); Band 8 (385 to 500 GHz, submillimeter-wave); and Band 10 (787 to 950 GHz, Terahertz-wave).

The frequency band observable with the Band 8 receiver covers a wide range of radio emission lines from various atoms and molecules.

Among them, one of the most attractive targets for many astronomers is the emission from atomic carbon at 492 GHz.

What can we expect to see from it?The main component of the cosmic gas is hydrogen. The abundance of carbon is only 1/3000 of that of hydrogen, although carbon is the third most abundant element in the universe.

The cosmic gas can be classified into three groups by its temperature and density; "plasma cloud" (number density of plasma particles: 0.01 per 1 cm3, temperature: several million degrees Celsius), "atomic cloud" (number density of atom: 10 per 1 cm3, temperature: -160 degrees Celsius), and "molecular cloud" (number density of molecule: 10000 per 1 cm3, temperature: - 260 degrees Celsius).

Dense regions of atomic cloud grow into molecular cloud, and molecular cloud with increased density becomes a seedbed of stars. On the other hand, molecules composing molecular cloud dissociate into atoms when exposed to intense ultraviolet light. Detailed study of the distributions of atomic cloud and molecular cloud gives us insights into the evolution of cosmic gas.

In particular, observation of carbon atom is important not only in studying the distribution and characteristics of atomic cloud, but also in exploring chemistry in the universe because various complex molecules are formed from chemical reactions between carbon atom and other atoms such as oxygen and hydrogen.

So far, observations in the 500 GHz band, including emission line from cosmic carbon atom, have been made with single dish radio telescopes such as the University of Tokyo's Mt. Fuji Submillimeter Telescope and Caltech Submillimeter Observatory (CSO).

The typical spatial resolution of those observations is 15 arcseconds or larger (1 arcsecond corresponds to 1/3600 of 1 degree), which is far worse than the resolution of existing 8-meter class optical telescopes (0.1 arcsecond).

ALMA is the first radio interferometer which allows observations in this frequency range with remarkably improved resolution compared to single dish telescopes.

This time, the Band 8 receivers were installed in five 7-m antennas developed by Japan and achieved a high resolution of 3.5 arcseconds. By installing the receiver into all the ALMA antennas, the resolution becomes even better by 400 times. Astronomers around the world have high expectations for observations with Band 8.

Researchers find phosphate in more soluble form on Mars

Synthetic crystals of the calcium phosphate mineral whitlockite similar to those used to produce the extraterrestrial mineral merrillite. 

If life ever arose on Mars, merrillite may have been a major source of biologically required phosphate. Largest crystal are ~1mm. 

Credit: C. T. Adcock / University of Nevada Las Vegas 

A trio of researchers at the University of Nevada has found that phosphate found in minerals on Mars, is far more soluble than it is in natural Earth minerals.

In their paper published in the journal Nature Geoscience, the researchers describe how they synthesized mineral types found on Mars and then tested how well they dissolved in water releasing phosphate as compared to samples from natural Earth minerals.

Most scientists agree that phosphate is a key ingredient for life. Put another way, they believe that life couldn't have evolved without it.

For that reason, scientists have been studying ways in which minerals that contain phosphate could have broken down to allow the phosphate to escape.

Such studies have thus far found that minerals that hold phosphate on Earth are not very soluble—they don't break down easily when soaked in sea water.

That has led to what Earth scientists call "the phosphate problem." How did life get started on Earth if there wasn't enough phosphate around when life was first beginning?

Some have suggested the answer is that it didn't, instead, it started on another planet, such as Mars, and made its way here via meteorites.

Prior research has already shown that Mars has much more phosphate than does Earth. In this new effort, the team in Nevada looked at minerals that exist on Mars to see if they might be more soluble in water as well.

Lacking samples from Mars to test, the researchers synthesized chlorapatite and merrillite in their lab—two common phosphate bearing minerals found on the Red Planet.

They then soaked samples in several tubs, each with a different pH level for varying amounts of time. As they did so, they measured how much phosphate made its way into the water and how long it took.

In analyzing their results, the researchers found that more phosphate made its way into the water with both types of minerals and they did so at a faster rate than minerals that contain phosphate found naturally on Earth.

In some cases, they report that the Mars rocks released phosphate up to 45 percent faster than Earth rocks.

The findings by the team don't prove that life began on Mars and migrated to Earth—after all, scientists have yet to prove life ever existed Mars. But it does add some credence to the argument that perhaps life did start somewhere other than our home planet, which if true, might mean it's still out there waiting for us to discover it.

More information: Readily available phosphate from minerals in early aqueous environments on Mars, Nature Geoscience (2013) DOI: 10.1038/ngeo1923

TED Ed Video: The Higgs Field explained - Don Lincoln

One of the most significant scientific discoveries of the early 21st century is surely the Higgs boson, but the boson and the Higgs Field that allows for that magic particle are extremely difficult to grasp.

Fermilab's Don Lincoln outlines an analogy (originally conceived by David Miller) that all of us can appreciate, starring a large dinner party, a raucous group of physicists, and Peter Higgs himself.

Lesson by Don Lincoln, animation by Powerhouse Animation Studios Inc.

Other informative animated videos are available here

Ultracold Big Bang Experiment Simulates Evolution of Early Universe

Scientists created this detailed, all-sky picture of the infant universe from nine years of data from the orbiting Wilkinson Microwave Anisotropy Probe. 

The image reveals 13.77 billion year old temperature fluctuations—shown as color differences—that correspond to the seeds that grew to become the galaxies. 

Physicists now are using clouds of ultracold atoms in a vacuum chamber to simulate the growth of structure in the early universe. 

Credit: NASA/WMAP Science Team

Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the big bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago.

"This is the first time an experiment like this has simulated the evolution of structure in the early universe," said Cheng Chin, professor in physics.

Cheng Chin

Chin and his associates reported their feat in the Aug. 1 edition of Science Express, and it will appear soon in the print edition of Science.

Chin pursued the project with lead author Chen-Lung Hung, PhD'11, now at the California Institute of Technology, and Victor Gurarie of the University of Colorado, Boulder.

Their goal was to harness ultracold atoms for simulations of the big bang to better understand how structure evolved in the infant universe.

The cosmic microwave background is the echo of the big bang. Extensive measurements of the CMB have come from the orbiting Cosmic Background Explorer in the 1990s, and later by the Wilkinson Microwave Anisotropy Probe and various ground-based observatories, including the UChicago-led South Pole Telescope collaboration.

These tools have provided cosmologists with a snapshot of how the universe appeared approximately 380,000 years following the Big Bang, which marked the beginning of the universe.

It turns out that under certain conditions, a cloud of atoms chilled to a billionth of a degree above absolute zero (-459.67 degrees Fahrenheit) in a vacuum chamber displays phenomena similar to those that unfolded following the big bang, Hung said.

"At this ultracold temperature, atoms get excited collectively. They act as if they are sound waves in air," he said.

The dense package of matter and radiation that existed in the very early universe generated similar sound-wave excitations, as revealed by COBE, WMAP and the other experiments.

The synchronized generation of sound waves correlates with cosmologists' speculations about inflation in the early universe.

"Inflation set out the initial conditions for the early universe to create similar sound waves in the cosmic fluid formed by matter and radiation," Hung said.

Journal Reference:
C.-L. Hung, V. Gurarie, C. Chin. From Cosmology to Cold Atoms: Observation of Sakharov Oscillations in a Quenched Atomic Superfluid. Science, 2013; DOI: 10.1126/science.1237557

HD 189733b: A Giant Blue Alien Planet where it Rains Molten Glass

This illustration shows HD 189733b, a huge gas giant that orbits very close to its host star HD 189733. 

The planet's atmosphere is scorching with a temperature of over 1000 degrees Celsius, and it rains glass, sideways, in howling 7000 kilometer-per-hour winds.

Credit: NASA, ESA, M. Kornmesser

There's a "blue marble" alien planet just 63 light-years from Earth, but the world is anything but friendly to life.

Researchers say the blue colour in the atmosphere likely comes from a rain of molten glass.

This super-hot glass rain is just one consequence of the close proximity between the gas giant alien planet HD189733b and its sun, which causes daytime temperatures to soar as high as 1,700 degrees Fahrenheit (930 degrees Celsius), scientists said.

A fresh set of observations of the planet in X-rays also suggest HD189733b has an outer atmosphere that is far larger than expected.

These surprise finds are all signals that so-called hot Jupiter alien planets are worthy of study on their own, even though they are hostile planets to life, researchers said.



Hot Jupiters are large, roughly Jupiter-sized planets that become very hot by circling tight around their stars.

These worlds have been described as planetary daredevils because they orbit so close to their parent stars that they risk being consumed.

Often, one side of the planet is tidally locked to the star, exposing that side to scorching hot temperatures, while leaving the other side permanently turned away.

Hot Jupiters are easy to spot from a distance because as they pass in front of a star, their disc blots out a large portion of the star's light; HD189733b causes a three per cent drop in its star's light, for example.

The planets' gravitational pull often causes their parent stars to wobble, too.

While common in the universe, however, Hot Jupiters are totally different than what denizens of Earth's solar system encounter.

In our case, small, rocky planets orbit close to the star and the gas giants are much farther out.

The latest observations of HD189733b are challenging some theories of planetary formation and are just one of the reasons Hot Jupiters are earning more attention from astronomers these days.

"At first considered to be the 'chaff' researchers would have to wade through to get to the fainter Earth-like worlds, hot Jupiters are now attracting their own attention," NASA scientists wrote in a recent Science@NASA post.

ISS Astronauts Take Time Off for US Labour Day Holiday

Five of the six Expedition 36 crew members are pictured in the International Space Station's Kibo laboratory during a daily planning conference. 

Pictured from bottom left are European Space Agency astronaut Luca Parmitano, NASA astronaut Chris Cassidy, both flight engineers; Russian cosmonaut Pavel Vinogradov, commander; NASA astronaut Karen Nyberg and Russian cosmonaut Fyodor Yurchikhin, both flight engineers. 

Credit: NASA

Americans across the United States will pause to celebrate the Labor Day holiday on Monday (Sept. 2), even space travelers soaring high above Earth aboard the International Space Station.

There are two American astronauts — NASA's Karen Nyberg and Chris Cassidy — currently serving on the space station's six-person crew, and they are expecting a light work day Monday, NASA officials said.

While station astronauts typically take a break from their usual duties on holidays, they still may need to do a little work.

Nyberg and European Space Agency (ESA) astronaut Luca Parmitano might take part in a quick training session to prepare for the arrival of an unmanned cargo-carrying Cygnus spacecraft, NASA spokesman Josh Byerly told reporters.

The Cygnus capsule is scheduled to launch from NASA's Wallops Flight Facility on Wallops Island, Va., atop an Antares rocket on Sept. 17.

It will mark the first Cygnus test flight to International Space Station.

The unmanned cargo ship was built by the commercial spaceflight company Orbital Sciences Corp.

But aside from Cygnus training, Nyberg and the rest of the station's Expedition 36 crew will likely have the chance to chat with their loved ones in honor of the U.S. holiday.

Space station residents can call their families whenever they have time and they can send emails and video link with the ground.

This year's Labor Day in space should be more subdued than last year's holiday. In 2012, astronauts on the space station were prepping for an extra spacewalk after a sticky bolt prevented NASA astronaut Sunita Williams and Japanese (JAXA) spaceflyer Akihiko Hoshide from replacing a faulty piece of hardware on the outside of the station.

The station is about the size of a five bedroom house has the wingspan of a football field. Construction of the station began in 1998 and it has been continuously staffed with crews of spaceflyers since 2000.

NASA Chandra: Astronomers discover why SMBHs consume less material

A composite image of the region around Sagittarius A* (Sgr A*), the supermassive black hole in the center of the Milky Way. 

X-ray emission from NASA's Chandra X-ray Observatory is shown in blue, and infrared emission from the Hubble Space Telescope is shown in purple and yellow. 

The inset shows a close-up view of Sgr A* in X-rays only, covering a region half a light year wide.

The diffuse emission is from hot gas captured by the black hole and being pulled inwards. 

Less than 1% of this material reaches the black hole's event horizon, or point of no return, because much of it is ejected. 

Credit: X-ray: NASA/UMass/Q.D. Wang et al.; IR: NASA/STScI

Using NASA's super-sensitive Chandra X-ray space telescope, a team of astronomers led by Q. Daniel Wang at the University of Massachusetts Amherst has solved a long-standing mystery about why most super massive black holes (SMBH) at the centers of galaxies have such a low accretion rate—that is, they swallow very little of the cosmic gases available and instead act as if they are on a severe diet.

"In principle, super massive black holes suck in everything," Wang says, "but we found this is not correct."

Astronomers once thought SMBHs with their intense gravitational pull indiscriminately devoured all sorts of stars, dust and other matter in epic amounts.

But in recent years, using X-ray emissions as a measure of heat given off by powerful gravitational forces, they unexpectedly found that most SMBH accrete matter at very low levels.

In fact, SMBHs' signature X-ray emissions, which come from an area much larger than the black holes themselves, are often so surprisingly faint that the objects are difficult to distinguish from their galaxy centers.

"There has been a big mystery about why most of these black hole signals are so faint," says Wang, an expert in deep space X-ray analysis.

Now, taking advantage of very long observation times with the Chandra instrument and their detailed knowledge of the nearest SMBH, Sagittarius A* (Sgt A*), about 26,000 light years away at the center of our own Milky Way galaxy, he and an international team of astronomers tested the leading accretion models.

For the first time, they were able to pinpoint and discriminate among X-ray sources near Sgt A* and identify exactly what the SMBH is feeding on. The advance is described in the current issue of Science.

To explain the faint X-ray signals, some astronomers had theorized that emissions from regions around SMBH had nothing to do with the black hole itself but rather with concentrations of low-mass stars associated with SMBHs.

Wang adds, "There are also a huge number of young, massive stars as well as low-mass stars near these SMBHs, so it's very crowded in the downtown area of the galaxy. Hard to tell what was going on."

This artist's illustration shows the environment around Sgr A*, the supermassive black hole found some 26,000 light years away at the center of our Galaxy. 

The red disk depicts hot gas that has been captured by the black hole and is being pulled inwards. 

The source of the hot gas is young, massive stars, shown in blue, orbiting around Sgr A*. 

The illustration also shows a large amount of material being thrown outwards, a key factor in explaining why there is so little radiation from material near black holes. 

Credit: NASA/CXC/M. Weiss

"The massive stars have extremely high winds associated with them and the winds are colliding and swirling at very high speeds, which make the gases in this environment very hot. We found that first, the SMBH has difficulty in accreting such gases.

"Second, the gases are too hot for the black hole to swallow. Instead it rejects about 99 percent of this super hot material, only letting a small amount in. This makes sense because the hotter the gases, the more difficult it is for the black hole to pull them in."

A diet of cooler gases would accrete in a more orderly fashion, but the SMBH's sphere of influence and its ability to accrete or draw in new material both decrease with increasing gas temperatures, he points out.

Wang, who did this NASA-supported work while on four-month sabbatical as a Raymond and Beverly Sackler Distinguished Visiting astronomer at the University of Cambridge, U.K., points out, "Now we have physically resolved it and for the first time we've made the connection observationally between the massive stars moving around black holes and the X-ray emitting material."

"We can definitively rule out that these X-rays are coming from a concentration of low-mass stars. We don't see the expected energy signature predicted by that scenario."

The astronomers not only detected the X-ray source, he adds, but for the first time can describe its shape, which is elongated.

"Now we know what kind of material is getting into the black hole, though exactly how it happens is still another question."

More information: "Dissecting X-Ray–Emitting Gas Around the Center of Our Galaxy," by Q.D. Wang et al Science, 2013. On Arxiv: arxiv.org/abs/1307.5845