Old-looking galaxy in a young universe: Astronomers find dust in the early universe

This spectacular view from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 1689. The huge concentration of mass bends light coming from more distant objects and can increase their total apparent brightness and make them visible. One such object, A1689-zD1, is located in the box -- although it is still so faint that it is barely seen in this picture. New observations with ALMA and ESO's VLT have revealed that this object is a dusty galaxy seen when the Universe was just 700 million years old.  Credit: NASA; ESA; L. Bradley (Johns Hopkins University); R. Bouwens (University of California, Santa Cruz); H. Ford (Johns Hopkins University); and G. Illingworth (University of California, Santa Cruz)

Dust plays an extremely important role in the universe -- both in the formation of planets and new stars. But dust was not there from the beginning and the earliest galaxies had no dust, only gas. Now an international team of astronomers, led by researchers from the Niels Bohr Institute, has discovered a dust-filled galaxy from the very early universe. The discovery demonstrates that galaxies were very quickly enriched with dust particles containing elements such as carbon and oxygen, which could form planets. The results are published in the scientific journal, Nature.

Cosmic dust are smoke-like particles made up of either carbon (fine soot) or silicates (fine sand). The dust is comprised primarily of elements such as carbon, silicon, magnesium, iron and oxygen. The elements are synthesised by the nuclear combustion process in stars and driven out into space when the star dies and explodes. In space, they gather in clouds of dust and gas, which form new stars, and for each generation of new stars, more elements are formed. This is a slow process and in the very earliest galaxies in the history of the universe, dust had not yet formed.

But now a team of researchers have discovered a very distant galaxy that contains a large amount of dust, changing astronomers' previous calculations of how quickly the dust was formed.

"It is the first time dust has been discovered in one of the most distant galaxies ever observed -- only 700 million years after the Big Bang. It is a galaxy of modest size and yet it is already full of dust. This is very surprising and it tells us that ordinary galaxies were enriched with heavier elements far faster than expected," explains Darach Watson, an astrophysicist with the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen.

Darach Watson led the project, with Lise Christensen from the Dark Cosmology Centre and researchers from Sweden, Scotland, France and Italy.

Lucky location

Because the galaxy is very distant and therefore incredibly faint, it would not usually be detectable from Earth. But a fortunate circumstance means the light from it has been amplified. This is because a large cluster of galaxies called Abell 1689, lies between the galaxy and Earth. The light is refracted by the gravity of the galaxy cluster, thus amplifying the distant galaxy. The phenomenon is called gravitational lensing and it works like a magnifying glass.

"We looked for the most distant galaxies in the universe. Based on the colours of the light observed with the Hubble Space Telescope we can see which galaxies could be very distant. Using observations from the very sensitive instrument, the X-shooter spectrograph on the Large Telescope, VLT in Chile, we measured the galaxy's spectrum and from that calculated its redshift, i.e. the change in the light's wavelength as the object recedes from us. From the redshift we can calculate the galaxy's distance from us and it turned out to be, as we suspected, one of the most distant galaxies we know of to date," explains Lise Christensen, an astrophysicist at the Dark Cosmology Centre at the Niels Bohr Institute.

Early planet formation

Darach Watson explains that they then studied the galaxy with the ALMA telescopes, which can observe far-infrared wavelengths and then it became really interesting, because now they could see that the galaxy was full of dust. He explains that young stars in early galaxies emit hot ultraviolet light. The hot ultraviolet radiation heats the surrounding ice-cold dust, which then emits light in the far-infrared.

"It is this far-infrared light, which tells us that there is dust in the galaxy. It is very surprising and it is the first time that dust has been found in such an early galaxy. The process of star formation must therefore have started very early in the history of the universe and be associated with the formation of dust. The detection of large amounts of solid material shows that the galaxy was enriched very early with solids which are a prerequisite for the formation of complex molecules and planets," explains Darach Watson.

Now the researchers hope that future observations of a large number of distant galaxies using the ALMA telescopes could help unravel how frequently such evolved galaxies occur in this very early epoch of the history of the universe.

Source: University of Copenhagen - Niels Bohr Institute

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Is not there Big Bang ? A quantum equation show that the universe has no beginning

The universe could have existed forever, according to a new model that applies quantum correction terms to complement the theory of general relativity of Einstein. The model can also explain dark matter and dark energy.

The widely accepted age of the universe, according to estimates of general relativity, is 13,800 million years. At first, everything was dealt a single infinitely dense point or, in other words, the singularity. After that point began to expand to trigger the Big Bang, considered the origin of the universe, has  Science Direct .

Although the Big Bang singularity arises directly and inevitably mathematics of general relativity, some scientists consider the problematic issue because mathematics can only explain what happened after and not before the singularity .

However, Ahmed Ali Farag, Benha University, Egypt, and Saurya Das University of Lethbridge, Canada, say the Big Bang singularity can be resolved by its new model in which the universe has no beginning nor end .

The researchers used Raychaudhuri equation and the Friedmann equations, which describe the expansion and evolution of the universe (including the Big Bang) in the context of general relativity. The model of Ali and Das contains elements of both quantum theory, of general relativity .

In physical terms, the model describes the universe as full of "quantum fluid" . Scientists propose that this fluid could be composed of gravitons, hypothetical massless particles that mediate the force of gravity.

To understand the origin of the universe, they analyzed the behavior of the fluid over time. Surprisingly, they found that this does not converge towards the singularity, but, on the contrary, the universe seems to have always existed . Although it was smaller in the past, says Das.

Source: RT

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Helicopter Could Be 'Scout' for Mars Rovers

Enter the Mars Helicopter, a proposed add-on to Mars rovers of the future that could potentially triple the distance these vehicles currently drive in a Martian day, and deliver a new level of visual information for choosing which sites to explore.

The helicopter would fly ahead of the rover almost every day, checking out various possible points of interest and helping engineers back on Earth plan the best driving route.

Scientists could also use the helicopter images to look for features for the rover to study in further detail. Another part of the helicopter's job would be to check out the best places for the rover to collect key samples and rocks for a cache, which a next-generation rover could pick up later.

The vehicle is envisioned to weigh 2.2 pounds (1 kilogram) and measure 3.6 feet (1.1 meters) across from the tip of one blade to the other. The prototype body looks like a medium-size cubic tissue box.

The current design is a proof-of-concept technology demonstration that has been tested at NASA's Jet Propulsion Laboratory, Pasadena, California.

Source: Nasa

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NASA's Dawn Spacecraft Captures Best-Ever View of Dwarf Planet

This animation of the dwarf planet Ceres was made by combining images taken by the Dawn spacecraft on January 25, 2015.

NASA's Dawn spacecraft has returned the sharpest images ever seen of the dwarf planet Ceres. The images were taken 147,000 miles (237,000 kilometers) from Ceres on Jan. 25, and represent a new milestone for a spacecraft that soon will become the first human-made probe to visit a dwarf planet.

"We know so little about our vast solar system, but thanks to economical missions like Dawn, those mysteries are being solved," said Jim Green, Planetary Science Division Director at NASA Headquarters in Washington.

At 43 pixels wide, the new images are more than 30 percent higher in resolution than those taken by NASA's Hubble Space Telescope in 2003 and 2004 at a distance of over 150 million miles (about 241 million kilometers). The resolution is higher because Dawn is traveling through the solar system to Ceres, while Hubble remains fixed in Earth orbit. The new Dawn images come on the heels of initial navigation images taken Jan. 13 that reveal a white spot on the dwarf planet and the suggestion of craters. Hubble images also had glimpsed a white spot on the dwarf planet, but its nature is still unknown.

"Ceres is a 'planet' that you've probably never heard of," said Robert Mase, Dawn project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "We're excited to learn all about it with Dawn and share our discoveries with the world."

As the spacecraft gets closer to Ceres, its camera will return even better images. On March 6, Dawn will enter into orbit around Ceres to capture detailed images and measure variations in light reflected from Ceres, which should reveal the planet's surface composition.

"We are already seeing areas and details on Ceres popping out that had not been seen before. For instance, there are several dark features in the southern hemisphere that might be craters within a region that is darker overall," said Carol Raymond, deputy principal investigator of the Dawn mission at JPL. "Data from this mission will revolutionize our understanding of this unique body. Ceres is showing us tantalizing features that are whetting our appetite for the detailed exploration to come."

Ceres, the largest body between Mars and Jupiter in the main asteroid belt, has a diameter of about 590 miles (950 kilometers). Some scientists believe the dwarf planet harbored a subsurface ocean in the past and liquid water may still be lurking under its icy mantle.

Originally described as a planet, Ceres was later categorized as an asteroid, and then reclassified as a dwarf planet in 2006. The mysterious world was discovered in 1801 by astronomer Giuseppe Piazzi, who named the object for the Roman goddess of agriculture, grain crops, fertility and motherly relationships.

"You may not realize that the word 'cereal' comes from the name Ceres. Perhaps you already connected with the dwarf planet at breakfast today," said JPL's Marc Rayman, mission director and chief engineer of the Dawn mission.

Powered by a uniquely capable ion propulsion system, Dawn also orbited and explored Vesta, the second most massive body in the asteroid belt. From 2011 to 2012, Dawn returned more than 30,000 images, 18 million light measurements and other scientific data about the impressive large asteroid. Vesta has a diameter of about 326 miles (525 kilometers).

"With the help of Dawn and other missions, we are continually adding to our understanding of how the solar system began and how the planets were formed," said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Virginia, designed and built the spacecraft. JPL is managed for NASA by the California Institute of Technology in Pasadena.

The framing cameras were provided by the Max Planck Institute for Solar System Research in Gottingen, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research in Berlin, and in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig.

The visible and infrared mapping spectrometer was provided by the Italian Space Agency and the Italian National Institute for Astrophysics, was built by Selex ES, and is managed by Italy's National Institute for Astrophysics and Planetology in Rome. The gamma ray and neutron detector was built by Los Alamos National Laboratory in New Mexico, and is operated by the Planetary Science Institute of Tucson, Arizona.

Source: Nasa

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The Ancient exoplanet discovery boosts chances of finding alien life

An artist's impression of the oldest known system of terrestrial-sized planets, Kepler-444. Tiago Campante/Peter Devine, University of Birmingham, Author provided Credit: By Daniel Huber, Astronomer at University of Sydney

One of the crucial variables in calculating the likelihood that alien life exists elsewhere in our galaxy is the number of stars that possess planetary systems, and the proportion of those planets that might be suitable for life.

So the discovery of no less than five sub-Earth-sized exoplanets orbiting an ancient star, Kepler-444, which is not too distant from our own solar system, has significant ramifications for the possibility we might one day run into ET.

Formed over 11-billion years ago, the Kepler-444 system proves that such small planets have existed through most of the history of our universe. And the more small planets that exist, the higher the chances that one of them (or one of their moons) might sit in the so-called “Goldilocks zone” that enables life to exist.

This remarkable discovery was made possible not only by the space-based NASA Kepler telescope but also a technique called asteroseismology.

Kepler continuously measured the brightness of more than 150,000 stars for four years. As planets orbit in front of the stellar disc they cause small dips in the brightness of the star, yielding information on the planet’s orbital period and size relative to the size of their host star.

More than 1,800 exoplanets have been discovered to date, including some Earth-sized planets in the habitable zone. Such discoveries have demonstrated that planets with favourable conditions for life may actually be common.

But the age of the host stars – and therefore the age of the planets – was often unknown. This is because the clues that give a hint to the age of a star tend to be hidden beneath its visible surface.

Using asteroseismology to date a star

An artist’s impression of Kepler-10, illustrating the paths of sound waves in the stellar interior which can be used to determine the fundamental properties – including age – of planet host stars. Gabriel Perez Diaz, Instituto de Astrofisica de Canarias

Fortunately, the variability in the brightness of stars offers a way to resolve this problem using asteroseismology.

Stars with similar and cooler temperatures than our sun transport energy to their surface through the up-flow and down-flow of gas that flows due to the interplay of buoyancy and gravity. The turbulent motion of the gas excites pressure waves to travel through the stellar interior.

The frequency of these waves – also referred to as oscillations – are determined by the sound speed, which in turn depends on the stellar interior structure and composition.

These oscillations also travel to different depths within the star, thereby offering a way to probe the structure by observing the oscillations. As the core properties of the star change with time, such changes are imprinted in the oscillation frequency patterns.

Conveniently, we can measure stellar oscillations using the same data we use to discover transiting planets. Thus we were able to use asteroseismology to study a fascinating planetary system in exquisite detail and to determine the age of the host star.


Kepler-444: An ancient laboratory for planetary and stellar astrophysics

Comparison of the sizes of inner solar system planets to the planets discovered in the Kepler-444 system. Daniel Huber & NASA

Unlike our solar system, however, the Kepler-444 planets orbit their host star in less than 10 days. Even taking into account the cooler temperature of Kepler-444 compared to our sun, this places these ancient planets well outside the habitable zone.

Despite the rather hostile environment, Kepler-444 marks an important milestone to understand whether life may be common outside the solar system. While the Kepler mission has previously demonstrated that small planets are abundant, Kepler-444 proves that such planets have formed for most of the history of our universe.

If life can form on Earth-sized planets in the habitable zone of other stars, this implies that it may have formed on distant planets long before life emerged here on Earth.

Source: University of Sydney

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Black hole on a diet creates a 'changing look' quasar

This artist's rending shows "before" and "after" images of a changing look quasar.
Credit: By Jim Shelton

Yale University astronomers have identified the first “changing look” quasar, a gleaming object in deep space that appears to have its own dimmer switch.

The discovery may offer a glimpse into the life story of the universe’s great beacons.

Quasars are massive, luminous objects that draw their energy from black holes. Until now, scientists have been unable to study both the bright and dim phases of a quasar in a single source.

As described in an upcoming edition of The Astrophysical Journal, Yale-led researchers spotted a quasar that had dimmed by a factor of six or seven, compared with observations from a few years earlier.

“We’ve looked at hundreds of thousands of quasars at this point, and now we’ve found one that has switched off,” said C. Megan Urry, Yale’s Israel Munson Professor of Astronomy and Astrophysics, and the study’s co-author. “This may tell us something about their lifetimes.”

Stephanie LaMassa, a Yale associate research scientist and principal investigator for the study, noticed the phenomenon during an ongoing probe of Stripe 82 — a sliver of the sky found along the Celestial Equator. Stripe 82 has been scanned in numerous astronomical surveys, including the Sloan Digital Sky Survey.

“This is like a dimmer switch,” LaMassa said. “The power source just went dim. Because the life cycle of a quasar is one of the big unknowns, catching one as it changes, within a human lifetime, is amazing.”

Even more significant for astronomers was the weakening of the quasar’s broad emission lines. Visible on the optical spectrum, these broad emission lines are signatures of gas that is too distant to be consumed by a black hole, yet close enough to be “excited” by energy from material that does fall into a black hole.

The change in the emission lines is what told researchers that the black hole had essentially gone on a diet, and was giving off less energy as a result. That’s when the “changing look” quasar hit its dimmer switch, and most of its broad emission lines disappeared.

The Yale team analyzed a variety of observation data, including recent optical spectra information and archival optical photometry and X-ray spectra information. They needed to rule out the possibility the quasar merely appeared to lose brightness, due to a gas cloud or other object passing in front of it.

The findings may prove invaluable on several fronts. First, they provide direct information about the intermittent nature of quasar activity; even more intriguingly, they hint at the sporadic activity of black holes.

“It makes a difference to know how black holes grow,” Urry said, noting that all galaxies have black holes, and quasars are a phase that black holes go through before becoming dormant. “This perhaps has implications for how the Milky Way looks today.”

Additionally, there is the chance the quasar may fire up again, showing astronomers yet another changing look.

“Even though astronomers have been studying quasars for more than 50 years, it’s exciting that someone like me, who has studied black holes for almost a decade, can find something completely new,” LaMassa said.

(Illustration by Michael S. Helfenbein)

Source: Yale university

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Astronomers discover a replica solar system

This image shows Kepler-444 and its five orbiting planets. (Courtesy of Peter Devine and Tiago Campante/University of Birmingham)

Scientists have located an ancient solar system, dating back to the dawn of the galaxy, which appears to be a miniature version of the inner planets in our own solar system.

An international research group, including Yale University professors of astronomy Sarbani Basu and Debra Fischer, announced the discovery Jan. 27 in The Astrophysical Journal. The findings are the result of observations made by the NASA Kepler spacecraft over a period of four years.

The old, Sun-like star, named Kepler-444, has five orbiting planets with sizes between those of Mercury and Venus. Kepler-444 formed 11.2 billion years ago, when the universe was less than 20% of its current age. This makes Kepler-444 the oldest known system of terrestrial-sized planets. The Kepler-444 system was already older than our own solar system is today when our Sun and planets were born.

“This system shows that planet formation could take place under very different conditions from the ones in which our solar system was formed and has implications for estimating the total number of planets in our galaxy, and other galaxies,” Basu said.

The five planets in the Kepler-444 system have orbits that are equivalent to less than one-tenth of Earth’s distance from the Sun. The Kepler-444 planets are rocky and Earth-like, but their exact compositions are uncertain.

The scientists carried out their research using asteroseismology — listening to the host star’s natural resonances, which are caused by sound trapped within it. These oscillations lead to miniscule changes or pulses in the star’s brightness, allowing researchers to measure the star’s diameter, mass, and age. The planets were then detected from the dimming that occurs when the planets transited, or passed across, the stellar disc. This fractional fading in the intensity of starlight enabled scientists to measure accurately the sizes of the planets relative to the size of the star.

“There are far-reaching implications for this discovery,” said lead author Tiago Campante of the University of Birmingham (U.K.). “We now know that Earth-sized planets have formed throughout most of the universe’s 13.8-billion-year history, which could provide scope for the existence of ancient life in the galaxy.”

The research collaboration involved nearly two-dozen institutions in the United States, England, Denmark, Portugal, Australia, Germany, and Italy.

Source: Yale university

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SOHO and Hinode Offer New Insight Into Solar Eruptions

Scientists are trying to understand the precise details of what creates giant explosions in the sun's atmosphere, such as this solar eruption from Oct. 14, 2012, as seen by NASA's Solar Dynamic Observatory. Image Credit: NASA/SDO/Amari

The sun is home to the largest explosions in the solar system. For example, it regularly produces huge eruptions known as coronal mass ejections – when billions of tons of solar material erupt off the sun, spewing into space and racing toward the very edges of the solar system. Scientists know that these ejections, called CMEs, are caused by magnetic energy building up on the sun, which suddenly releases. But the details of what causes the build up and triggers the release are not precisely understood.

A journal paper in Nature magazine on Oct. 23, 2014, used data from NASA missions to present an example of how something called a magnetic flux rope builds up over time until it is so unstable that even the slightest perturbation will send it flying. Understanding what triggers CMEs is crucial not only for better understanding of our sun, but also to lay the groundwork for predicting when such giant explosions might happen.

"We looked at a well-studied CME from 2006," said Tahar Amari first author on the Nature paper at Ecole Polytechnique in France. "We knew that there had been a great deal of data available for this CME and much analysis already done, but no one had created a comprehensive picture of what happened."

Amari and his colleagues used a traditional meteorology technique to examine the event: Gather observations from the days before the CME to track how the event grew over time. They used observations from the European Space Agency and NASA's Solar and Heliospheric Observatory, or SOHO, and the Japanese Aerospace Exploration Agency and NASA's Hinode, as well as from the Paris-Meudon Observatory.

Scientists created this model to examine the magnetic field before a giant solar eruption – a coronal mass ejection – which occurred on Dec. 13, 2006. The orange lines show magnetic field lines. The grey line represents what's called a flux rope, which built up the day before the event. Image Credit: Amari/Ecole Poytechnique

The team wanted to see if they could distinguish between two broad theories about how the magnetic energy develops. The first model describes a situation in which a series of loops of magnetic fields on the sun – known as an arcade – is the start of every active region CME. 

This arcade has a weak point at the top, a place where the energy from below can burst through once it's great enough. During the eruption a flux rope forms, which can be seen inside the CME as it surges away from the sun.

The second model assumes that the flux rope is there before the CME erupts. In this theory, no weak point is required. Instead, the flux rope gains more and more energy, and becomes increasingly unstable until a disturbance on the sun causes it to release the energy out into space.

Amari and his team used magnetic data from the surface obtained by Hinode, but they also needed magnetic data for the sun's atmosphere, the corona, which is strongly affected by its magnetic field.

"The corona is so hot that most of the techniques to measure the magnetic field don't work," said Amari. "So we developed an efficient and accurate model to compute the magnetic field there, based on the data we had from the surface, and the equations governing the physics of the low corona above active regions."

With these two data sets in hand, the team examined what happened in the four days before the 2006 CME erupted. They could see the magnetic energy building; it was clear something was emerging. Only, however, on the last day did a flux rope develop and only then did it have enough energy built up to power a CME eruption. At this point, some small disruption was enough of a nudge to make the flux rope erupt.

A model of the eruption of a giant magnetic rope that led to a coronal mass ejection on the sun in December 2006.

A model of the eruption of a giant magnetic rope that led to a coronal mass ejection on the sun in December 2006. The model showed that magnetic fields built up for several days before the eruption.

"In this case no weak point up in the atmosphere was needed to allow the energy to be released," said Amari. "There is, instead, a kind of critical value of energy, a value we can compute based on seeing an active magnetic region on the sun. Beneath that value the magnetic field will stay quiet. Above that, it is likely to erupt. There is also a critical height for rising flux rope, beyond which the magnetic loops above can no longer keep it confined."

The team explored the initial conditions from this event and put the information into another dynamical model the team had developed. The simulation mirrored what was actually seen, with an eruption occurring only when the critical energy and height were reached on the last day.

Amari points out that just because this CME contained a flux rope prior to eruption, it doesn't mean that other CMEs can’t erupt based on other physical catalysts. But it clearly describes one mechanism that is at work on the sun.

By measuring and calculating the magnetic fields on the sun, coupled with determining how to measure the critical tipping point where a CME can erupt, the paper offers new ways to determine the possibility of eruption from any given active area on the sun.

Source: Nasa

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The state of astronomy before Hubble and the difficulties of observing from the ground that drove the need for a space telescope' Videos

This video looks at the state of astronomy before Hubble and the difficulties of observing from the ground that drove the need for a space telescope. Image Credit: Space Telescope Science Institute

Dr. Nancy Grace Roman, first chief astronomer at NASA’s then Office of Space Science and the one who set up NASA’s astronomy program in the 1960s, speaks about the importance of building and launching a space telescope instead of building duplicates of the Earth-based Palomar 200-inch telescope.

"Astronomers have wanted for generations actually to get a telescope above the atmosphere,” Roman said. “I like to describe the atmosphere being something like looking through an old stained glass window… The glass has defects in it and that sort of keeps you from getting a sharp picture and the atmosphere also has defects." 

"The very sharp images it would produce would allow you to see things that were much fainter than would ever be possible from the ground," said C. Robert O'Dell, of Vanderbilt University in Nashville, Tennessee. O'Dell leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of the iconic Ring Nebula.
The video addresses several challenges at the time of Hubble's creation, including digital imaging at a time when the industry was in its infancy. The video also speaks on how the telescope has far exceeded its initial life-span.

The 4 minute and 23 second video was produced by STScI. The "Hubble 25th Anniversary" video series is available in HQ, large and small Quicktime formats, HD, large and small WMV formats, and HD, large and small Xvid formats.

WATCH VIDEO HERE



Source: Nasa Hubble

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Ballooning Offers a Multi-Disciplinary Platform for Performing Research in a Space-Like Environment

A view from the edge of space, the High Energy Replicated Optics to Explore the Sun (HEROES) telescope is a hard X-ray telescope, sensitive in the 20-75 keV range and designed to fly on a high-altitude balloon platform. The HEROES telescope is one example of a balloon payload designed to fly at this altitude. This payload launched from Fort Sumner, NM, in the Fall of 2013, and the flight lasted for 27 hours. At its maximum altitude of just over 39 km, the telescope pointed at the Sun, the black hole candidate GRS 1915+105, and the Crab Nebula, with the capability to carry out high resolution imaging and spectroscopy. The HEROES Project is a collaboration between NASA Marshall Space Flight Center and Goddard Space Flight Center and was funded through the NASA Hands On Project Experience Training Opportunity. (Photo Credit: R. Salter, Columbia Scientific Balloon Facility)

New discoveries are being made on an annual basis by researchers flying their instruments on a high-altitude balloon platform. Ease of access to ballooning, relatively low cost and the potential for quick turn-around response times create a large appeal for using this platform to perform novel science and to train new scientists. This appeal is reinforced by the availability of a range of balloon sizes to accommodate various payload types, multiple launch sites (for shorter and longer duration flights), and more sophisticated gondolas.

Since the 1950s, and the invention of the 'natural' shaped polyethylene balloon, there has been a surge in the quality and amount of science being performed on this platform. The flexibility, reliability and relatively low-cost of the high-altitude balloon platform, over that of a satellite, makes for an attractive means of carrying out novel science in a space-like environment across multiple disciplines, which include: high-energy astrophysics (particle, x-ray and gamma-ray), IR/sub-mm (CMB to planetary), heliophysics, geospace and atmospheric research.

Existing balloons are capable of carrying large payloads to high altitudes for flight durations lasting tens of days. The longest flight to date was that of SuperTIGER in 2012-2013 on a vented zero-pressure balloon. This payload weighed 2,025 kg (not including flight straps) and flew to a maximum altitude of ~39.6 km. The entire flight lasted for just over 55 days. The development of the Super-Pressure Balloon holds promise for achieving even longer flights launching from Antarctica (> 100 days), and Long Duration Balloon flights from mid-latitude launch sites. This capability, combined with improved payload pointing, light-weight gondolas and more sophisticated instrumentation will enable scientists to make new discoveries and develop novel instrumentation suitable for orbital missions. This platform will also continue to provide a training ground for the next generation of scientists and engineers.

Additional co-authors include I. Steve Smith from the Space Science and Engineering Division at Southwest Research Institute, and W. Vernon Jones from the Science Mission Directorate, Astrophysics Division at NASA Headquarters. The corresponding author for this study is Jessica A. Gaskin, Jessica.Gaskin@nasa.gov.

Source: WS

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Black holes follow the rules

Artist's impression of a black hole at the centre of a galaxy. Credit: Gabriel Pérez Díaz.

Rather than having random sizes, massive black holes seem to follow a predictable rule in relation to the physical properties of the galaxy in which they are located.

Research at Swinburne University of Technology has shown that it is possible to predict the masses of black holes in galaxies for which it was previously thought not possible.

In large galaxies, the central black hole is related to the mass of the spheroid-shaped distribution of stars at the centre of the galaxy, known as the galaxy’s 'bulge'.

Some astronomers have claimed that the size of black holes at the centres of galaxies with small bulges was unrelated to the bulge.

Even the four million solar mass black hole in the bulge of our Milky Way galaxy was thought to be arbitrarily low relative to trends defined by their more massive, and therefore easier to detect, counterparts.

However, in previous work Swinburne Professor Alister Graham, lead-author of the current research, identified a new relationship involving black holes in galaxies with small bulges.  He demonstrated that the black hole in the bulge of the Milky Way was not set by chance but instead followed an astronomical rule.

“The formula is quadratic, in that the black hole mass quadruples every time the bulge mass doubles,” Professor Graham said. “Therefore, if the bulge mass increases 10 times, the black hole mass increases 100 times.”

Now, after studying more than 100 galaxies with black holes 4 to 40 times less massive than our Milky Way's black hole, they too have been found to follow this same rule.

"It turns out that there is yet more order in our Universe than previously appreciated,” Professor Graham said.

"This is exciting not just because it provides further insight into the mechanics of black hole formation, but because of the predictions it allows us to make."

The gravitational collapse of massive stars can produce black holes up to a few tens of times the mass of our Sun. And black holes that are one-tenth of a million to ten billion times the mass of our Sun have been identified at the centres of giant galaxies. However, there is a missing population of intermediate-mass black holes.

Astronomers don't know if this is because of observational difficulties in finding them, or if the massive black holes at the centres of galaxies start life as 100,000 solar mass seed black holes that formed in the early Universe.

This latest result, which extends the new rule to 40-times lower masses, gives astronomers some confidence that it may extend even further, so the smallest bulges might host these missing intermediate-mass black holes. 

"If confirmed, it would imply tremendous black hole appetites", co-author of the study, Dr Nicholas Scott, said. "There would need to be a dramatic growth of these small black holes relative to their host bulge, with the bulges growing via the creation of stars out of gas clouds while the black holes devour both gas and stars."

The researchers have identified a few dozen candidate galaxies in which they think intermediate-mass black holes may be hiding.  Future observations, with facilities such as the Square Kilometre Array and space-based X-ray telescopes, are expected to help resolve this black hole mystery.

Source: Swinburne

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Tail discovered on long-known asteroids

The faint tail can be seen in active asteroid 62412. Image courtesy of Scott Sheppard

Washington, D.C.--A two-person team of Carnegie's Scott Sheppard and Chadwick Trujillo of the Gemini Observatory has discovered a new active asteroid, called 62412, in the Solar System's main asteroid belt between Mars and Jupiter. It is the first comet-like object seen in the Hygiea family of asteroids. Sheppard will present his team's findings at the American Astronomical Society's Division of Planetary Sciences meeting and participate today in a press conference organized by the society.

Active asteroids are a newly recognized phenomenon. 62412 is only the 13th known active asteroid in the main asteroid belt. Sheppard and Trujillo estimate that there are likely about 100 of them in the main asteroid belt, based on their discovery.

Active asteroids have stable orbits between Mars and Jupiter like other asteroids. However, unlike other asteroids, they sometimes have the appearance of comets, when dust or gas is ejected from their surfaces to create a sporadic tail effect. Sheppard and Trujillo discovered an unexpected tail on 62412, an object which had been known as a typical asteroid for over a decade. Their findings reclassify it as an active asteroid. The reasons for this loss of material and subsequent tail in active asteroids are unknown, although there are several theories such as recent impacts or sublimation from solid to gas of exposed ices.

"Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn't, but that is all changing as we realize that not all of these objects show activity all of the time," Sheppard said.

In the past, asteroids were thought to be mostly unchanging objects, but an improved ability to observe them has allowed scientists to discover tails and comas, which are the thin envelope of an atmosphere that surrounds a comet's nucleus.

"We're actually looking anew through our deep survey at a population of objects that other people cannot easily observe, because we're going much deeper," Sheppard said, explaining why they were able to see that 62412 was active when it had been considered a typical main belt asteroid for 15 years.;

Discoveries such as this one can help researchers determine the processes that cause some asteroids to become active. Sheppard will discuss his and Trujillo's theories about the genesis of 62412's activity. They found that 62412 has a very fast rotation that likely shifts material around its surface, some of which may be emitted to form the comet-like appearance. The tail may be created directly from ejected material off the fast rotating nucleus, or from ice within the asteroid subliming into water vapor after being freshly exposed on the surface. They also find a density for 62412 typical of primitive asteroids and not consistent with the much lower-density comets. Further monitoring of this unusual object will help confirm the activity's source.

Sheppard and Trujillo have a paper about this work in press at The Astronomical Journal.


Source: NASA

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Radiation from early universe found key to answer major questions in physics

The UC San Diego astrophysicists employed the HuanTran Telescope in Chile to measure the polarization of the cosmic microwave background. Credit: POLARBEAR

Astrophysicists at UC San Diego have measured the minute gravitational distortions in polarized radiation from the early universe and discovered that these ancient microwaves can provide an important cosmological test of Einstein's theory of general relativity. These measurements have the potential to narrow down the estimates for the mass of ghostly subatomic particles known as neutrinos.

The radiation could even provide physicists with clues to another outstanding problem about our universe: how the invisible "dark matter" and "dark energy," which has been undetectable through modern telescopes, may be distributed throughout the universe.

The scientists are publishing details of their achievement in the June issue of the journal Physical Review Letters.

The UC San Diego scientists measured variations in the polarization of microwaves emanating from the Cosmic Microwave Background -- or CMB -- of the early universe. Like polarized light (which vibrates in one direction and is produced by the scattering of visible light off the surface of the ocean, for example), the polarized "B-mode" microwaves the scientists discovered were produced when CMB radiation from the early universe scattered off electrons 380,000 years after the Big Bang, when the cosmos cooled enough to allow protons and electrons to combine into atoms.

Astronomers had hoped the unique B-mode polarization signature from the early cosmos would allow them to effective "see" portions of the universe that are invisible to optical telescopes as gravity from denser portions of the universe tug on the polarized light, slightly deflecting its passage through the cosmos during its 13.8 billion year trip to Earth. Through a process called "weak gravitational lensing," the distortions in the B-mode polarization pattern, they hoped, would allow astronomers to map regions of the universe filled with invisible "dark matter" and "dark energy" and well as provide a test for general relativity on cosmological scales.

The recent discovery confirms both hunches. By measuring the CMB polarization data provided by POLARBEAR, a collaboration of astronomers working on a telescope in the high-altitude desert of northern Chile designed specifically to detect "B-mode" polarization, the UC San Diego astrophysicists discovered weak gravitational lensing in their data that, they conclude, permit astronomers to make detailed maps of the structure of the universe, constrain estimates of neutrino mass and provide a firm test for general relativity.

"This is the first time we've made these kinds of measurements using CMB polarization data," said Chang Feng, the lead author of the paper and a physics graduate student at UC San Diego who conducted his study with Brian Keating, an associate professor of physics at the university and a co-leader of the POLARBEAR experiment. "This was the first direct measurement of CMB polarization lensing. And the amazing thing is that the amount of lensing that we found through these calculations is consistent with what Einstein's general relativity theory predicted. So we now have a way to verify general relativity on cosmological scales."

The POLARBEAR experiment examined a small (30 degree square) region of the sky to produce high resolution maps of B-mode polarization, which enabled the team to determine that the amplitude of gravitational fluctuations they measured was consistent with the leading theoretical model of the universe, known as the Lambda Cold Dark Matter cosmological model. Another team Keating's group collaborates with, based at the Harvard-Smithsonian Center for Astrophysics, called BICEP2, used a telescope at the South Pole to examine B-mode polarization across wide swaths of the sky. In March, it announced it had found evidence for a brief and very rapid expansion of the early universe, called inflation.

One of the most important questions in physics that can be addressed from these data is the mass of the weakly interacting neutrino, which was thought to have no mass, but current limits indicate that neutrinos have masses below 1.5 electron volts. Feng said the B-mode polarization data in his study, while consistent with the predictions of general relativity, are not statistically significant enough yet to make any firm claims about neutrino masses. But over the next year, he and Keating hope to analyze enough data from POLARBEAR, and its successor instrument -- the Simons Array -- to provide more certainty about the masses of neutrinos.

"This study is a first step toward using polarization lensing as a probe to measure the mass of neutrinos, using the whole universe as a laboratory," Feng said.

"Eventually we will be able to put enough neutrinos on a 'scale' to weigh them -- precisely measuring their mass," Keating says. "Using the tools Chang has developed, it's only a matter of time before we can weigh the neutrino, the only fundamental elementary particle whose mass is unknown. That would be an astounding achievement for astronomy, cosmology and physics itself."

The study was supported by grants from the National Science Foundation, National Aeronautics and Space Administration, the Simmons Foundation, and Irwin and Joan Jacobs.

Source: University of California - San Diego

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Exploding stars prove Newton's law of gravity unchanged over cosmic time

Remains of a Type Ia supernovae (G299.2-2.9). Credit: X-ray: NASA/CXC/U.Texas/S. Park et al, ROSAT; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF

Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.

Newton's gravitational constant, known as G, describes the attractive force between two objects, together with the separation between them and their masses. It has been previously suggested that G could have been slowly changing over the 13.8 billion years since the Big Bang.

If G has been decreasing over time, for example, this would mean that Earth's distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to much earlier points in Earth's history.

But researchers at Swinburne University of Technology in Melbourne have now analysed the light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.

"Looking back in cosmic time to find out how the laws of physics may have changed is not new" Swinburne Professor Jeremy Mould said. "But supernova cosmology now allows us to do this with gravity."

A Type 1a supernova marks the violent death of a star called a white dwarf, which is as massive as our Sun but packed into a ball the size of our Earth.

Our telescopes can detect the light from this explosion and use its brightness as a 'standard candle' to measure distances in the Universe, a tool that helped Australian astronomer Professor Brian Schmidt in his 2011 Nobel Prize winning work, discovering the mysterious force Dark Energy.

Professor Mould and his PhD student Syed Uddin at the Swinburne Centre for Astrophysics and Supercomputing and the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) assumed that these supernova explosions happen when a white dwarf reaches a critical mass or after colliding with other stars to 'tip it over the edge'.

"This critical mass depends on Newton's gravitational constant G and allows us to monitor it over billions of years of cosmic time -- instead of only decades, as was the case in previous studies," Professor Mould said.

Despite these vastly different time spans, their results agree with findings from the Lunar Laser Ranging Experiment that has been measuring the distance between Earth and the Moon since NASA's Apollo missions in the 1960s and has been able to monitor possible variations in G at very high precision.

"Our cosmological analysis complements experimental efforts to describe and constrain the laws of physics in a new way and over cosmic time." Mr Uddin said.

In their current publication, the Swinburne researchers were able to set an upper limit on the change in Newton's gravitational constant of 1 part in 10 billion per year over the past nine billion years.

The ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration between The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, the University of Queensland, The University of Western Australia and Curtin University, the latter two participating together as the International Centre for Radio Astronomy Research. CAASTRO is funded under the Australian Research Council Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government's Science Leveraging Fund.

The research is published this month in the Publications of the Astronomical Society of Australia.

Source: Swinburne University of Technology

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Plugging the hole in Hawking's black hole theory

Recently physicists have been poking holes again in Stephen Hawking's black hole theory -- including Hawking himself. For decades physicists across the globe have been trying to figure out the mysteries of black holes -- those fascinating monstrous entities that have such intense gravitational pull that nothing -- not even light -- can escape from them. Credit: Still image from video courtesy of Michigan State University

Recently physicists have been poking holes again in Stephen Hawking's black hole theory -- including Hawking himself. For decades physicists across the globe have been trying to figure out the mysteries of black holes -- those fascinating monstrous entities that have such intense gravitational pull that nothing -- not even light -- can escape from them. Now Professor Chris Adami, Michigan State University, has jumped into the fray.

The debate about the behavior of black holes, which has been ongoing since 1975, was reignited when Hawking posted a blog on Jan. 22, 2014, stating that event horizons -- the invisible boundaries of black holes -- do not exist.

Hawking, considered to be the foremost expert on black holes, has over the years revised his theory and continues to work on understanding these cosmic puzzles.

One of the many perplexities is a decades-old debate about what happens to information -- matter or energy and their characteristics at the atomic and subatomic level -- in black holes.

"In 1975, Hawking discovered that black holes aren't all black. They actually radiate a featureless glow, now called Hawking radiation," Adami said. "In his original theory, 

Hawking stated that the radiation slowly consumes the black hole and it eventually evaporates and disappears, concluding that information and anything that enters the black hole would be irretrievably lost."

But this theory created a fundamental problem, dubbed the information paradox.

Now Adami believes he's solved it.

"According to the laws of quantum physics, information can't disappear," Adami said. "A loss of information would imply that the universe itself would suddenly become unpredictable every time the black hole swallows a particle. That is just inconceivable. No law of physics that we know allows this to happen."

So if the black hole sucks in information with its intense gravitational pull, then later disappears entirely, information and all, how can the laws of quantum physics be preserved?

The solution, Adami says, is that the information is contained in the stimulated emission of radiation, which must accompany the Hawking radiation -- the glow that makes a black hole not so black. Stimulated emission makes the black hole glow in the information that it swallowed.

"Stimulated emission is the physical process behind LASERS (Light Amplification by Stimulated Emission of Radiation). Basically, it works like a copy machine: you throw something into the machine, and two identical somethings come out.

"If you throw information at a black hole, just before it is swallowed, the black hole first makes a copy that is left outside. This copying mechanism was discovered by Albert Einstein in 1917, and without it, physics cannot be consistent," Adami said.

Do others agree with Adami's theory that stimulated emission is the missing piece that solves the information paradox?

According to Paul Davies, cosmologist, astrobiologist and theoretical physicist at Arizona State University, "In my view Chris Adami has correctly identified the solution to the so-called black hole information paradox. Ironically, it has been hiding in plain sight for years. Hawking's famous black hole radiation is an example of so-called spontaneous emission of radiation, but it is only part of the story. There must also be the possibility of stimulated emission -- the process that puts the S in LASER."

With so many researchers trying to fix Hawking's theory, why did it take so long if it was hiding in plain sight?

"While a few people did realize that the stimulated emission effect was missing in Hawking's calculation, they could not resolve the paradox without a deep understanding of quantum communication theory," Adami said. Quantum communication theory was designed to understand how information interacts with quantum systems, and Adami was one of the pioneers of quantum information theory back in the '90s.

Trying to solve this information paradox has kept Adami awake many nights as demonstrated by his thick notebooks filled with 10 years of mathematical calculations.

So where does this leave us, according to Adami?

"Stephen Hawking's wonderful theory is now complete in my opinion. The hole in the black hole theory is plugged, and I can now sleep at night," he said.

Adami may now sleep well at night, but his theory is sure to keep other physicists up trying to confirm whether he has actually solved the mystery.

The study was co-authored by Greg Ver Steeg, University of Southern California and is published online in the journal Classical and Quantum Gravity.

Source: Michigan State University

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