ESA XMM-Newton: Inexplicable signal provides clue about dark matter

A sketch (not to scale) showing axions (blue) streaming out from the Sun, converting in the Earth's magnetic field (red) into X-rays (orange), which are then detected by the XMM-Newton observatory. 

Credit: University of Leicester

Cutting-edge paper by Professor George Fraser, who tragically died in March this year,and colleagues at the University of Leicester provides first potential indication of direct detection of Dark Matter, something that has been a mystery in physics for over 30 years.

Space scientists at the University of Leicester have detected a curious signal in the X-ray sky – one that provides a tantalising insight into the nature of mysterious Dark Matter.

The Leicester team has found what appears to be a signature of 'axions', predicted 'Dark Matter' particle candidates, something that has been a puzzle to science for years.

In a study being published on Monday 20 October in the Monthly Notices of the Royal Astronomical Society, the University of Leicester scientists describe their finding of a signal which has no conventional explanation.

As first author Professor George Fraser, who sadly died in March of this year, wrote: "The direct detection of dark matter has preoccupied physics for over thirty years."

Dark Matter, a kind of invisible mass of unknown origin, cannot be seen directly with telescopes, but is instead inferred from its gravitational effects on ordinary matter and on light.

Dark Matter is believed to make up 85% of the matter of the Universe.

"The X-ray background, the sky, after the bright X-ray sources are removed - appears to be unchanged whenever you look at it," explained Dr. Andy Read, also from the University of Leicester Department of Physics and Astronomy and now leading the paper.

"However, we have discovered a seasonal signal in this X-ray background, which has no conventional explanation, but is consistent with the discovery of axions."

This result was found through an extensive study of almost the entire archive of data from the European Space Agency's X-ray observatory, XMM-Newton, which will celebrate its 15th year in orbit this December.

Previous searches for axions, notably at CERN, and with other spacecraft in Earth orbit, have so far proved unsuccessful.

As Professor Fraser explains in the paper: "It appears plausible that axions, Dark Matter particle candidates, are indeed produced in the core of the Sun and do indeed convert to X-rays in the magnetic field of the Earth."

It is predicted that the X-ray signal due to axions will be greatest when looking through the sunward side of the magnetic field because this is where the field is strongest.

Dr. Read concludes: "These exciting discoveries, in George's final paper, could be truly ground-breaking, potentially opening a window to new physics, and could have huge implications, not only for our understanding of the true X-ray sky, but also for identifying the Dark Matter that dominates the mass content of the cosmos."

President of the Royal Astronomical Society Professor Martin Barstow, who is Pro-Vice-Chancellor, Head of the College of Science & Engineering and Professor of Astrophysics & Space Science at the University of Leicester said: "This is an amazing result. If confirmed, it will be first direct detection and identification of the elusive dark matter particles and will have a fundamental impact on our theories of the Universe."

More information: "Potential solar axion signatures in X-ray observations with the XMM-Newton observatory," G. W. Fraser, A. M. Read, S. Sembay, J. A. Carter, E. Schyns, Accepted (08/09/14) for publication in Monthly Notices of the Royal Astronomical Society (mnras.oxfordjournals.org/), Paper can be found on arXiv : arxiv.org/abs/1403.2436.

Satellite X-ray observations: Neutron star with doughnut-shaped magnetic field and axial wobble

An artist's impression of a magnetar with an intense torroidal magnetic field in its core. 

Credit: NASA /CXC /M.Weiss

When a massive star dies, it can collapse under its own gravity with such force that it produces a supernova, leaving behind an extremely dense remnant consisting almost entirely of neutrons, a neutron star.

Some neutron stars, known as magnetar, possess powerful magnetic fields, which are stronger than any other known magnetism in the Universe.

These intense magnetic fields somehow produce high-energy x-ray pulses, but this process is not well understood.

Kazuo Makishima from RIKEN's MAXI Team and Teruaki Enoto from the RIKEN Nishina Center for Accelerator-Based Science in collaboration with the University of Tokyo and NASA have now found evidence that the magnetar 4U 0142+61 'wobbles' about its rotational axis, implying that the sphericity of the star is distorted due to an intense donut-shaped magnetic field at its core.

"Magnetars emit high-energy 'hard' x-rays, but the origins of these emissions are unknown," explains Makishima.

"We observed 4U 0142+61 using the Suzaku x-ray astronomy satellite (formerly known as Astro-E2) to find out whether the magnetar's emissions change over time."

The magnetar had previously been measured to spin at a rate of one revolution in about 8 seconds and to produce x-ray pulses of the same period, but Makishima and his co-workers noticed slow fluctuations in the arrival times of the x-ray pulses.

They attributed these fluctuations to axial wobble, known as free precession.

The star's axis precesses with a period that differs very slightly from the star's rotation period, and the slow beat between the two periods changes the observed emissions.

"The idea of free precession was not in my mind when we started the data analysis," says Makishima, "but I was familiar with it through my long experience with spinning satellites."

"The precession is most likely caused by a slight deformation of the magnetar, and the deformation is possibly due in turn to internal magnetic fields that are even stronger than the external visible fields."

The findings suggest that the magnetar is deformed from a perfect sphere due to an extremely strong, tightly wound toroidal magnetic field buried deep in the star's core.

The results therefore support the hypothesis that the hard-x-ray pulses are produced by consuming magnetic energy.

Makishima's team plans to analyze a third dataset from 4U 0142+61 and search the Suzaku data for other magnetars that might show similar effects.

"We will also propose observations of these objects with ASTRO-H, the powerful successor to Suzaku, which will be launched in 2015," he says.

More information: Makishima, K., Enoto, T., Hiraga, J. S., Nakano, T., Nakazawa, K., Sakurai, S., Sasano, M. & Murakami, H. Possible evidence for free precession of a strongly magnetized neutron star in the magnetar 4U 0142+61. Physical Review Letters 112, 171102 (2014). DOI: 10.1103/PhysRevLett.112.171102

Astronomers reveal contents of mysterious black hole jets

This is a model of the black hole system with the jets that have been found to contain atomic matter. 

Credit: J. Miller-Jones (ICRAR) using software created by R. Hynes.

An international team of astronomers has answered a long standing question about the enigmatic jets emitted by black holes, in research published today in prestigious journal Nature.

Jets are narrow beams of matter spat out at high speed from near a central object, like a black hole.

"Although they have been observed for decades, we're still not sure what they are made of, or what powers them," ESO astronomer Dr María Díaz Trigo, lead author of the study, said.

The team studied the radio waves and X-rays emitted by a small black hole a few times the mass of the Sun.

The black hole in question was known to be active, but the team's radio observations did not show any jets, and the X-ray spectrum didn't reveal anything unusual.

However, a few weeks later, the team took another look and this time saw radio emissions corresponding to the sudden appearance of these jets, and even more interestingly, lines had appeared in the X-ray spectrum – the tell-tale signature of ordinary atoms – around the black hole.

During the first observation the X-ray emission can be fully described by emission from a standard accretion disc. 

Credit: Riccardo Lanfranchi

"Intriguingly, we found the lines were not where they should be, but rather were shifted significantly," Dr James Miller Jones from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), who led the radio observations, said.

The same effect occurs when a siren from a vehicle changes pitch as it moves towards or away from us, as the sound wave is shortened or lengthened by the movement.

During the second observation the appearance of a jet is detected in radio emission and the X-ray spectrum requires an additional component attributed to coronal emission above the disc and three narrow emission lines indicating the presence of baryons. 

Credit: Riccardo Lanfranchi

"It led us to conclude the particles were being accelerated to fast speeds in the jets, one directed towards Earth, and the other one in the opposite direction," team member Dr Simone Migliari from the University of Barcelona said.

Dr Miller-Jones said this is the first strong evidence of such particles in jets from a typical small black hole.

"We've known for a long time that jets contain electrons, but haven't got an overall negative charge, so there must be something positively charged in them too," Dr Miller Jones said.

"Until now it wasn't clear whether the positive charge came from positrons, the antimatter 'opposite' of electrons, or positively charged atoms. Since our results found nickel and iron in these jets, we now know ordinary matter must be providing the positive charge."

Positively charged atoms are much heavier than the positrons astronomers thought might make up the jets, and therefore the jets can carry away far more energy from the black hole than previously confirmed.

What's more, astronomers aren't sure whether the jets are powered by the spin of the rotating black hole itself, or whether they are instead launched directly from the disk of matter that surrounds the black hole.

"Our results suggest it's more likely the disk is responsible for channelling the matter into the jets, and we are planning further observations to try and confirm this," Dr Miller-Jones said.

Using the X-ray data, the team also determined the jets were moving at 66% of the speed of light, or 198,000 km/s, the most accurate determination to date of the jet speed from a run-of-the-mill black hole that's a few times the mass of the Sun.

For their observations, the team used the European Space Agency's XMM-Newton satellite to observe X-ray emission from the black hole, as well as CSIRO's Australia Telescope Compact Array for the radio observations.

More information: Nature paper: dx.doi.org/10.1038/nature12672

ESA X-ray Observatory: Super-dense star is first ever found suddenly slowing its spin

The magnetar 1E 2259+586 shines a brilliant blue-white in this false-colour X-ray image of the CTB 109 supernova remnant, which lies about 10,000 light-years away toward the constellation Cassiopeia. 

CTB 109 is only one of three supernova remnants in our galaxy known to harbor a magnetar. 

X-rays at low, medium and high energies are respectively shown in red, green, and blue in this image created from observations acquired by the European Space Agency's XMM-Newton satellite in 2002. 

Credit: ESA/XMM-Newton /M. Sasaki et al.

One of the densest objects in the universe, a neutron star about 10,000 light years from Earth, has been discovered suddenly putting the brakes on its spinning speed.

The event is a mystery that holds important clues for understanding how matter reacts when it is squeezed more tightly than the density of an atomic nucleus—a state that no laboratory on Earth has achieved.

The discovery by an international team of scientists will be published in the journal Nature on May 30, 2013.

The scientists detected the neutron star's abrupt slow-down with NASA's Swift observatory, a satellite with three telescopes whose science and flight operations are controlled by Penn State from the Mission Operations Center on the University Park campus.

"Because Swift has the ability to regularly measure the spin of this unusual star, we have been able to observe its surprising evolution," said Penn State astronomer Jamie Kennea, a coauthor of the Nature paper.

"This neutron star is doing something completely unexpected. Its speed of rotation has been dropping at an increasingly rapid rate ever since the initial sudden decrease in its spin."

Although astronomers have observed neutron stars suddenly speeding up their spins—an event called a "glitch"—they never before had observed a neutron star suddenly slowing down.

"We've dubbed this event an 'anti-glitch' because it affected this star in exactly the opposite manner of every other clearly identified glitch seen in neutron stars," said co-author Neil Gehrels, the lead researcher on the Swift mission, at NASA's Goddard Space Flight Center.

The star is in the Northern Hemisphere sky in the constellation Cassiopeia.

More Information: Nature, 2013. dx.doi.org/10.1038/nature12159

NASA Chandra Image: A Surprisingly Bright Superbubble

Credits: X-ray: NASA/CXC/U.Mich./S.Oey, IR: NASA/JPL, Optical: ESO/WFI/2.2-m

This composite image shows a superbubble in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way located about 160,000 light years from Earth.

Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44, so named because it is the 44th nebula in a catalogue of such objects in the Magellanic Clouds.

The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas.

The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas. X-rays from NASA's Chandra X-ray Observatory (blue) show hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (red) outline where the dust and cooler gas are found.

The optical light from the 2.2-m Max-Planck-ESO telescope (yellow) in Chile shows where ultraviolet radiation from hot, young stars is causing gas in the nebula to glow.

A long-running problem in high-energy astrophysics has been that some superbubbles in the LMC, including N44, give off a lot more X-rays than expected from models of their structure.

These models assume that hot, X-ray emitting gas has been produced by winds from massive stars and the remains of several supernovas.

A Chandra study published in 2011 showed that there are two extra sources of N44's X-ray emission not included in these models: supernova shock waves striking the walls of the cavities, and hot material evaporating from the cavity walls.

The Chandra observations also show no evidence for an enhancement of elements heavier than hydrogen and helium in the cavities, thus ruling out this possibility as a third explanation for the bright X-ray emission.

Only with long observations making full use of the capabilities of Chandra has it now become possible to distinguish between different sources of the X-rays produced by superbubbles.

ESA XMM-Newton: Aftermath of a Supernova

Suspended in time and space, the aftermath of a massive star’s dramatic ending in a supernova explosion is captured by ESA’s XMM-Newton space observatory.

Nested knots of hot gas glowing green at X-ray wavelengths – equivalent to millions of degrees celsius – fill the structured central region of this expanding supernova remnant.

Supernova remnants are the glowing fireballs created after a massive star – greater than eight of our Suns – has exhausted its fuel supply and collapses in on itself, ejecting its remaining layers of gas in a blinding explosion.

A neutron star or black hole may remain at the heart of the explosion, obscured by the expanding shell of ejected material that also contains material swept up from the interstellar medium – the space between stars.

In this image, two bright spots at the right edge of the shell are lit up by the interaction of shock waves with the surrounding medium. This supernova remnant is only a few thousand years old – the expansion of the shock will take hundreds of thousands of years to slow down.

By studying supernova remnants at X-ray wavelengths, astronomers can identify the abundance and distribution of different elements forged during the last stages of the star’s life.

This information can provide clues about the mass of the progenitor star and the dynamics of the explosion.

Blue and white specks in and around the remnant are foreground and background stellar objects.

Z Machine: The Art and Science of Making White Dwarfs in the Desert - YouTube

The Z Machine at Sandia National Laboratories in Albuquerque, New Mexico is the stuff of comic book legend.

The massive X-ray generator is capable of creating what astronomer Don Winget calls “star stuff,” the same dense plasma that makes up the universe’s white dwarf stars.

According to the University of Texas, for a few nanoseconds the Z Machine creates an electrical current so strong that it equals more than six times the total amount of energy released by all of the power plants in the entire world.

Then, in a tiny chamber, tungsten wires are vaporised by the electricity and hydrogen plasma is formed along with a magnetic field that causes it to implode.

As the magnetic field “pinches” the plasma for an incredibly brief moment, the result is a massive burst of X-ray radiation and the formation of a tiny piece of white dwarf star, which is 10,000 times more dense than the surface of our sun.

Winget describes seeing a bright flash of light and feeling a giant boom move through him, followed by the rise and fall of a seismic wave that causes concentric circles of dust to expand outward from the laboratory.

All of this takes place in a giant chamber that measures 100 feet across and 20 feet high, originally built to model nuclear weapons.

Now Winget and his team hope to use it to study how stars are formed and what goes on in the center of them.

It could also be a step towards harnessing nuclear fusion to meet the Earth’s growing energy needs. For now, it’s the best alternative we have to simply observing stars from across the galaxy

Searching Deep into Space and the Universe

NASA may eventually keep an eye on super-hot galaxy clusters thanks to an invention inspired by a roll of Scotch tape.

The center of a galaxy cluster houses a soup of superheated gas and plasma, in which electrons bounce around at about the speed of light.

Scientists are keen to get a glimpse of the intense X-rays emitted from these fiery centers, which could shed light on the physics at work in the centers of galaxy clusters and help researchers understand the evolution of the universe

But there's a problem: The special mirrors -- which are curved and nested inside a cylindrical assembly -- that scientists use to collect these X-rays are expensive to make. In June, NASA launched the NuStar X-ray telescope to look for black holes and other celestial structures.

The NuStar has a mirror with an effective area of 300 square centimeters, but scientists would need a mirror with an effective area of about a meter squared to see the cosmic rays from galaxy clusters.

"With current technology, it is prohibitively expensive to build that," says NASA astrophysicist Maxim Markevitch. But Markevitch hit upon a possible solution, thanks to the aforementioned roll of tape. He thought that they could build a larger mirror more cheaply using tape coated on one side with reflective material -- probably a sandwich of carbon and platinum -- and then wound into a roll.

NASA NuStar: X-ray mission reaches orbit

The Nuclear Spectroscopic Telescope Array begins its mission using high-energy x-rays to uncover some of the most powerful structures in the universe.

Image: NASA via UStream

At noon Eastern time on Wednesday, NuSTAR (Nuclear Spectroscopic Telescope Array) blasted towards low-Earth orbit from a Pegasus XL rocket, after it was dropped from the belly of a carrier jet circling near the Kwajalein Atoll in the Pacific Ocean.

The X-ray mission, a low-cost NASA mission in its small Explorer line of competitive missions, is expected to discover hundreds of new supermassive black holes that lie in the hearts of distant galaxies.

A lot is riding on NuSTAR — it is one of few missions in sight for X-ray astronomers. Just last week, GEMS, a similar-looking mission that would have gathered polarized X-ray light, was canceled because of budget overruns.

While NuSTAR is no replacement for general purpose X-ray observatories like Chandra and XMM-Newton, it will have unprecedented sensitivity in the “hard”, or high-energy, X-ray part of the spectrum.

Fifteen minutes after launch, the science payload had separated from the rocket. By 12:22 pm EDT, all five of NuSTAR’s solar panels had been deployed successfully.

It will be another week before the most nerve-wracking phase of the mission begins — the 26 minutes during which a deployable mast will unfurl itself so that NuSTAR can reach its full 10-metre focal length.

RHESSI Will Use Venus Transit to Improve Measurements of the Sun's Diameter

The RHESSI (Ramaty High Energy Solar Spectroscopic Imager) satellite focuses on the highest energy x-rays and gamma-rays produced by the sun, helping to observe solar flares of all shapes and sizes.

The satellite is pointed toward the sun, and constantly in rotation, which provides a serendipitous bit of side research: by monitoring the limb of the sun on its four second rotation cycle, RHESSI's Solar Aspect System (SAS) has produced ten years worth of precise measurements of the sun's diameter.

This has already provided scientists with one of the most accurate measurements of what's called the oblateness of the sun, which is the difference between the diameter from pole to pole and the equatorial diameter.

With the new data obtained during the Venus Transit on June 5-6, 2012, the RHESSI team hopes to improve the knowledge of the exact shape of the sun and provide a more accurate measure of the diameter than has previously been obtained.

For one thing, the sharpness of the Venus disk as it crosses the sun will help determine the detailed optical properties of the telescope and calibrate the instrument's so-called plate scale, the exact angular size of each pixel.

With this improvement in hand, RHESSI can re-calibrate its already highly accurate observations of the sun's horizon. To further this aim, the science team has set the instrument to look at 64 pixels across the sun's limb, rather than its customary four.

The RHESSI team has hopes that they may be able to provide an unprecedentedly accurate measurement of the sun's size.

ESA XMM-Newton: X-ray satellite's breakthrough in mapping black holes

A veteran space telescope observing with X-ray eyes has made a breakthrough in helping to understand the supermassive black holes at the centre of galaxies.

Astronomers using the European Space Agency's (ESA) XMM-Newton satellite identified an "echo" within the galaxy NGC 4151, 45 million light-years away in the constellation of Canes Venatici, that they had long been searching for.

Galaxies such as NGC 4151 are known as active galaxies because they have brilliant centres which emit billions of times more energy than the Sun. These are lit up by material streaming in to a spinning monster black hole containing the mass of millions of stars.

A signature of these cosmic cannibals is a broad line in the X-ray region of the spectrum caused by excited and highly energetic iron atoms. This radiation is produced when a mystery X-ray source shines onto the whirling disk of matter spilling into the black hole, known as the accretion disk.

Astronomers know that these X-ray sources flare and they predicted that when this happened the broad iron line would brighten too after an interval depending on how long the X-rays took to light up the accretion disk in that strange physical environment.

Sadly these echoes of the flares were each too weak for XMM-Newton or NASA's powerful X-ray telescope Chandra to see individually. But an international team led by Dr Abderahmen Zoghbi, of the University of Maryland in the US, realised that if they could combine the echoes from several flares, then these might then become detectable.

They tested their theory using data from NGC 4151 which has an active nucleus powered by a black hole 50 million times the mass of the Sun. The galaxy's accretion disk was thought to be capable of producing more easily detectable echoes that would reverberate for a particularly long time.

An artist's impression of XMM-Newton in orbit. Credit: ESA

XMM-Newton has observed the galaxy extensively since the year 2000, building up the X-ray equivalent of a four-day photographic exposure. This has revealed numerous echoes, proving the astronomers' technique.

It allowed them to calculate that the X-ray source must lie around 640,000 km (400 million miles) above the supermassive black hole's accretion disk. Despite the black hole's incredible mass, that event horizon lies only half as far from it as the Earth's distance from the Sun. The team's work is published in the Monthly Notices of the Royal Astronomical Society.

Dr Zoghbi said: "Our analysis confirms some long-held ideas about active galactic nuclei and gives us a sense of what we can expect when a new generation of space-based X-ray telescopes eventually becomes available."

NASA's newest X-ray telescope, NuSTAR, is due to launch later this month from the Kwajalein Atoll in the central Pacific Ocean and is expected to study black holes in greater detail than ever.

ESA XMM Newton X-Ray Image: Galaxy NGC 4151

Credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration

This image shows the spiral galaxy NGC 4151, located at a distance of about 45 million light years from us.

NGC 4151 is a Seyfert galaxy and hosts one of the brightest active galactic nuclei (AGN) known at X-ray wavelengths.

The supermassive black hole lying at the centre of NGC 4151 has a mass of about 50 million solar masses.

Observations performed with ESA's XMM-Newton X-ray observatory have revealed X-rays emitted and then reflected by ionised iron atoms very close to the central black hole.

By measuring the time delays occurring in these 'reverberation' events, scientists have been able to map the vicinity of a black hole in unprecedented detail.

NASA Chandra X-Ray Observatory: Pink Opaque

An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. 

The discovery, made by astronomers using data from NASA's Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in X-rays as a million suns radiate at all wavelengths.

Researchers used Chandra to discover a new ultraluminous X-ray source, or ULX. 

These objects give off more X-rays than most binary systems, in which a companion star orbits the remains of a collapsed star. These collapsed stars form either a dense core called a neutron star or a black hole. 

The extra X-ray emission suggests ULXs contain black holes that might be much more massive than the ones found elsewhere in our galaxy.

A paper describing these results will appear in the May 10, 2012, issue of The Astrophysical Journal.

Image Credits: X-ray: NASA/CXC/Curtin University/R. Soria et al., Optical: NASA/STScI/ Middlebury College/F. Winkler et al.

ESA SRON JAXA Astro-H: A New space telescope to explore the violent Universe

European astronomers will be able to explore the universe with a powerful new Japanese space telescope thanks to an agreement recently signed.

Officials from the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) will cooperate in building and operating a satellite called Astro-H.

The orbiting observatory will watch the heavens with X-ray eyes, the latest in a number of space telescopes that can view this part of the spectrum beyond that of visible light. X-rays are emitted by extremely hot events at temperatures ranging from several million to several hundred million degrees Celsius.

Watching them will allow space scientists to observe some of the most extreme phenomena in the Universe including supernova explosions, neutron stars, black holes and the centres of active galaxies.

It will also help them to probe the large-scale structure of the Universe, including clusters of galaxies, and discover how it has evolved over billions of years. It will also help show how matter behaves in extreme gravitational fields.

JAXA’s Dr Tadayuki Takahashi, who invented the technology behind the camera, said: "We are aiming to quickly turn this technology to practical use."

The deal to work together on this exciting mission was signed last month by Professor Alvaro Giménez Cañete, ESA Director of Science and Robotic Exploration, and Dr Junjiro Onoda, Director General of the Japanese Institute of Space and Astronautical Science (ISAS).

ESA will provide JAXA with hardware components and support for operations and users. In return, astronomers at institutions in ESA countries will be granted observing time on the Astro-H mission.

NASA's Goddard Spaceflight Center is also contributing instrumentation to Astro-H, formerly known as NeXT, in collaboration with the University of Wisconsin.

The telescope is due to be launched in 2014 from the Tanegashima Space Centre in Southern Japan and will be placed in low-Eath orbit, which is high enough to be clear of the atmosphere which absorbs X-rays and makes them unobservable on the ground.

Astro-H will carry an array of spectrometers and imagers. But it also offers a prime example of how space science can have direct benefits to life back on Earth.

The spacecraft is being equipped with a gamma-ray detector that will observe the dying gasps of stars that go supernova.

The precision that this instrument is capable of will also be used on the ground to help Japan clean up contamination left by the Fukushima disaster after the massive earthquake in 2011.

Pulsar Stars to act as a Navigation Aid for Spacecraft

Spacecraft could one day navigate through the cosmos using a particular type of dead star as a kind of GPS.

German scientists are developing a technique that allows for very precise positioning anywhere in space by picking up X-ray signals from pulsars.

These dense, burnt-out stars rotate rapidly, sweeping their emission across the cosmos at rates that are so stable they rival atomic clock performance.

This timing property is perfect for interstellar navigation, says the team.

If a spacecraft carried the means to detect the pulses, it could compare their arrival times with those predicted at a reference location.

This would enable the craft to determine its position to an accuracy of just five kilometres anywhere in the galaxy.

"The principle is so simple that it will definitely have applications," said Prof Werner Becker from the Max-Planck Institute for Extraterrestrial Physics in Garching.

"These pulsars are everywhere in the Universe and their flashing is so predictable that it makes such an approach really straightforward," he told BBC News.

Prof Becker has been describing his team's research here at the UK National Astronomy Meeting in Manchester.

The proposed technique is very similar to that employed in the popular Global Positioning System, which broadcasts timing signals to the user from a constellation of satellites in orbit.

But GPS only works on, or just above, the Earth so it has no use beyond our planet.

Currently, mission controllers wanting to work out the position of their spacecraft deep in the Solar System will study the differences in time radio communications take to travel to and from the satellite. It is a complex process and requires several antennas dotted across the Earth.

It is also a technique that is far from precise, and the errors increase the further away the probe moves.

For the most distant spacecraft still in operation - Nasa's Voyager satellites, which are now approaching the very edge of the Solar System, some 18 billion km away - the errors associated with their positions are on the order of several hundred km.

ESA Planck and Fermi: Galactic Haze

This all-sky image shows the distribution of the Galactic Haze seen by ESA's Planck mission at microwave frequencies superimposed over the high-energy sky as seen by NASA's Fermi Gamma-ray Space Telescope.

The Planck data (shown here in red and yellow) correspond to the Haze emission at frequencies of 30 and 44 GHz, extending from and around the Galactic Centre.

The Fermi data (shown here in blue) correspond to observations performed at energies between 10 and 100 GeV and reveal two bubble-shaped, gamma-ray emitting structures extending from the Galactic Centre.

The two emission regions seen by Planck and Fermi at two opposite ends of the electromagnetic spectrum correlate spatially quite well and might indeed be a manifestation of the same population of electrons via different radiation processes.

Synchrotron emission associated with the Galactic Haze seen by Planck exhibits distinctly different characteristics from the synchrotron emission seen elsewhere in the Milky Way. Diffuse synchrotron emission in the Galaxy is interpreted as radiation from highly energetic electrons that have been accelerated in shocks created by supernova explosions.

Compared to this well-studied emission, the Galactic Haze has a 'harder' spectrum, meaning that its emission does not decline as rapidly with increasing frequency.

Several explanations have been proposed for this unusual behaviour, including enhanced supernova rates, galactic winds and even annihilation of dark-matter particles. Thus far, none of them have been confirmed and the issue remains open.

The Planck image includes the mask that has been used in the analysis of the data to exclude regions with strong foreground contamination due to the Galaxy's diffuse emission. The mask also includes strong point-like sources located over the whole sky.

Credits: ESA/Planck Collaboration (microwave); NASA/DOE/Fermi LAT/D. Finkbeiner et al. (gamma rays)

NASA Chandra: Milky Way’s Black Hole Devouring Asteroids

Astronomers from U.S. space agency Nasa and the University of Leicester in the UK have discovered a giant black hole that is vapourising and devouring asteroids. This black hole is located at the centre of the Milky Way galaxy.

Astronomers have detected X-ray flares from Sagittarius A - a super massive black hole - at least once in a day.

The brightness of the flares keeps varying from time to time and the flares last a few hours. These were detected from NASA's Chandra X-ray Observatory.

Sagittarius A is surrounded by a huge thick cloud that contains trillions of asteroids and comets. Asteroids passing within a 100 million miles of the black hole - roughly the distance between the Earth and the sun - seem to be torn into pieces by the tidal forces from the black hole.

These fragments are then vaporized by friction as they pass through the hot, thin gas flowing onto Sagittarius A. The process is similar to a meteor heating up and glowing as it falls through the Earth's atmosphere. A flare is produced when it enters the black hole and the remains of the asteroid are swallowed eventually by the black hole.

According to the astronomers, a huge asteroid that is located near a black hole can generate the huge flares that can easily be observed through Chandra. However, the smaller asteroids could be difficult to spot because the flares they generate would be fainter.

Astronomers are also planning, sometime in the future, to learn more about the frequency and brightness of flares. The hope is that this work will help them understand the formation of asteroids and planets in the harsh environment of Sagittarius A.

"An asteroid's orbit can change if it ventures too close to a star or planet near Sagittarius A," said Sergei Nayakshin from the University of Leicester, "If it's thrown toward the black hole, it's doomed."

NuStar: The Nuclear Spectroscopic Telescope Array

NuSTAR, The Nuclear Spectroscopic Telescope Array, will image the sky for the first time in the high energy X-ray (6-79 keV) region of the electromagnetic spectrum.

Our view of the universe in this spectral window has been limited previously. NuSTAR is scheduled to launch March 14, 2012, from an aircraft operating out of Kwajalein Atoll in the Marshall Islands.

Here, NuSTAR is seen undergoing a solar array illumination test.

Credit: NASA

eROSITA: German scientists ready for the hunt on dark energy

"With eROSITA we will be able to systematically probe the Universe in depth, we can look back in time to where the Universe was half its current age," explains Peter Predehl, who is leading the eROSITA project team. 

"While the previous X-ray all-sky survey by ROSAT was mainly concerned with the local Universe, eROSITA will enable us to map out the large scale structure in the Universe."

The German and Russian partners of the new eROSITA X-ray space observatory have now agreed on how to split the data from the first four years of an all sky survey.

This decision was announced at the first dedicated eROSITA conference in Garmisch-Partenkirchen and will enable German astronomers to work with the first full sky X-ray survey since the one carried out by the ROSAT satellite some 20 years ago.

The conference is attended by more than 150 astronomers from many different countries and fields of astronomy, showing the broad interest of the international astronomical community in this new observatory that is to be launched in 2013.

The eROSITA X-ray telescope, which is currently under construction by an international consortium led by the Max Planck Institute for Extraterrestrial Physics (MPE) will perform the first imaging all-sky survey in the medium energy X-ray range up to 10 keV with an unprecedented spectral and angular resolution.

With the data collected, astronomers will be able to detect and measure not only some 500 000 active stars but also about 100 000 groups and clusters of galaxies and up to three million new, distant supermassive black holes in active galactic nuclei.

The agreement between the German MPE and the Space Research Institute of the Russian Academy of Sciences (IKI), the two main scientific partners of eROSITA, specifies that German astronomers from all the institutions involved will receive data covering 20 000 square degrees of sky - an area hundreds of times bigger than the largest area observed with the XMM-Newton X-ray telescope.

While this telescope and its sister, the Chandra X-ray space observatory, are designed for deep observations of tiny areas, eROSITA was specifically developed for large scale observations.

"With eROSITA we will be able to systematically probe the Universe in depth, we can look back in time to where the Universe was half its current age," explains Peter Predehl, who is leading the eROSITA project team. "While the previous X-ray all-sky survey by ROSAT was mainly concerned with the local Universe, eROSITA will enable us to map out the large scale structure in the Universe."

Analysing the large-scale structure evolution as traced by the hot, X-ray emitting gas, will allow the scientists to put new constraints on the mysterious dark energy, which is causing the accelerated expansion of the Universe. While the discovery of this effect was honoured by the Nobel Prize in physics this year, the nature of dark energy remains an open question.

Chandra X-Ray Observatory: Black Hole rips star apart

This artist impression illustrates the tremendous gravitational pull of a giant black hole on a passing star.

The doomed object is first stretched by tidal forces until it is torn apart.

Most of the gas making up the star is lost from the system but some of it is trapped by the black hole and forms a disc of gas around it.

In the disc, the gas is heated to millions of degrees and emits in the X-rays, before disappearing forever, swallowed by the black hole.

It is precisely the signature of this disc that ESA's XMM-Newton has detected.

Credits: ESA and Stefanie Komossa (Max Planck Institute for Extraterrestrial Physics)