Thursday, December 30, 2010

Sparkle

NGC 1275
Image Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: A. Fabian (Institute of Astronomy, University of Cambridge, UK)

This Hubble Space Telescope image of galaxy NGC 1275 reveals the fine, thread-like filamentary structures in the gas surrounding the galaxy. The red filaments are composed of cool gas being suspended by a magnetic field, and are surrounded by the 100-million-degree Fahrenheit hot gas in the center of the Perseus galaxy cluster.

The filaments are dramatic markers of the feedback process through which energy is transferred from the central massive black hole to the surrounding gas. The filaments originate when cool gas is transported from the center of the galaxy by radio bubbles that rise in the hot interstellar gas.

At a distance of 230 million light-years, NGC 1275 is one of the closest giant elliptical galaxies and lies at the center of the Perseus cluster of galaxies.

The galaxy was photographed in July and August 2006 with Hubble's Advanced Camera for Surveys.

Tuesday, December 28, 2010

Planck clocks up 500 days of scanning the sky

The whole sky as seen by Planck
Credit: ESA / LFI and HFI Consortia


This week (27th Dec) marks 500 days since Planck started scanning the sky on 14th August 2009. Once every minute, Planck has spun on its axis to map rings around the sky. Now well into its third sky survey, Planck is more than half-way through its mission, and is mapping the sky at nine different wavelengths bands ranging from 0.3mm up to 1cm.

Planck's primary mission is to map the Cosmic Microwave Background, relic radiation from the early Universe, released just 400,000 years after the Big Bang. But the early Universe is not the only object which shines in microwave light. The gas and dust in our own Galaxy glows brightly, clouding the view of the Cosmic Microwave Background. The wide wavelength coverage of Planck is the solution.

By scanning the sky multiple times, Planck is building up a picture of which components of our Galaxy are seen at each wavelength. In July 2010, Planck's first all-sky map was released, showing the power of such wide wavelength coverage. The dust in our Galaxy is shown in blue and white, with gas in pink. This gas and dust is located in the disc of our Galaxy, which is seen edge-on from Earth and makes a band across the centre of this image.

The Cosmic Microwave Background is visible at the top and bottom of the image, looking away from the bright disc of the Galaxy. By comparing the emission seen at all its wavelengths, scientists working on Planck will be able to get a much clearer understanding of the Early Universe. Doing so takes a long time, and these cosmological results are not expected for around two years.

Astronomers are also studying the dust and gas in our own Galaxy, which mark the places where stars are forming. Planck is making maps of the star formation on the largest scales, which can be studied in more detail by other telescopes such as the Herschel Space Observatory.

But our own Galaxy is not the only one seen by Planck. In January 2011, a catalogue of the distant galaxies will be released, as well as very localised regions of star formation in our own galaxy.

Monday, December 27, 2010

The Veil Nebula

This image is part of the Eastern Veil Nebula, or NGC 6992, and it was obtained using the Wide Field Camera on the Isaac Newton Telescope. It is a three-colour composite made from data collected using filters to isolate the light emitted by hydrogen alpha (H-alpha), doubly ionised oxygen (OIII) and ionised sulfur (SII) atoms, and coded in the image as red, green and blue respectively. Credit: D. López (IAC). [ JPEG | TIFF | PDF (with text) ]

The Veil Nebula is part of the Cygnus Loop which comprises several NGC objects. Shown here is NGC 6992 in the Eastern Veil. The Veil Nebula is a faint supernova remnant that exploded some 5000 years ago, and since then it has been expanding on the sky to cover some 3 degrees. Its fine and intrincated filaments are attributed to a thin shock wave propagating into space and seen edge-on.

This image was obtained and processed by members of the IAC astrophotography group (A. Oscoz, D. López, P. Rodríguez-Gil and L. Chinarro).

More information:

Monday, December 20, 2010

Abell 644 and SDSS J1021+131: How Often do Giant Black Holes Become Hyperactive?

Abell 644 and DSS J1021+1312
Credit X-ray: NASA/CXC/Univ of Washington/D.Haggard et al, Optical: SDSS
JPEG (595.9 kb) - Tiff (37.3 MB) - PS (57.6 MB) - More Images

This two-panel graphic contains two composite images of galaxies used in a recent study of supermassive black holes. In each of the galaxies, data from NASA's Chandra X-ray Observatory are blue, and optical data from the Sloan Digital Sky survey are shown in red, yellow and white. The galaxy on the left, Abell 644, is in the center of a galaxy cluster that lies about 1.1 billion light years from Earth. On the right is an isolated, or "field," galaxy named SDSS J1021+1312, which is located about 900 million light years away. At the center of both of these galaxies is a growing supermassive black hole, called an active galactic nucleus (AGN) by astronomers, which is pulling in large quantities of gas.

A newly published study from Chandra tells scientists how often the biggest black holes in field galaxies like SDSS J1021+1312 have been active over the last few billion years. This has important implications for how environment affects black hole growth. The scientists found that only about one percent of field galaxies with masses similar to the Milky Way contain supermassive black holes in their most active phase. They also found that the most massive galaxies are the most likely to host these AGN, and that there is a gradual decline in the AGN fraction with cosmic time. Finally, the AGN fraction for field galaxies was found to be indistinguishable from that for galaxies in dense clusters, like Abell 644.

This study involves a survey called the Chandra Multiwavelength Project, or ChaMP, which covers 30 square degrees on the sky, the largest area covered of any Chandra survey to date. Combining Chandra's X-ray images with optical images from the Sloan Digital Sky Survey, about 100,000 galaxies were analyzed. Out of those, about 1,600 were bright in X-ray light, signaling possible AGN activity.

Fast Facts for Abell 644:

Scale: Image is 13.2 arcmin across. (36.7 million light years across)
Category: Groups & Clusters of Galaxies Quasars & Active Galaxies
Coordinates: (J2000) RA 08h 17m 25.6s | Dec -7° 30' 45''
Constellation: Hydra
Observation Dates: 3/26/2001
Observation Time: 8 hours 20 min
Obs. IDs: 2211
Color Code: X-ray (Blue), Optical (Red, Yellow, White)
Instrument: ACIS
References: Haggard, D. et al, 2010 ApJ 723:1447-1468
Distance Estimate: 9.55 billion light years (z=0.0701)

Fast Facts for SDSS J1021+1312:

Scale: Image is 3.2 arcmin across. (8.92 million light years across)
Category: Normal Galaxies & Starburst Galaxies Quasars & Active Galaxies
Coordinates: (J2000) RA 10h 21m 47.86s | Dec +13° 12' 28.19''
Constellation: Leo
Observation Dates: 1/31/2003
Observation Time: 2 hours 47 min
Obs. IDs/: 4107
Color Code: X-ray (Blue), Optical (Red, Yellow, White)
Instrument: ACIS
References: Haggard, D. et al, 2010 ApJ 723:1447-1468
Distance Estimate: 9.582 billion light years (z=0.085)

Friday, December 17, 2010

Herschel looks back in time to see today's stars bursting into life

An artist's rendition of the new SPIRE 'hot starburst'
Credit: NASA/CXC/M.Weiss

A UK-led international team of astronomers have presented the first conclusive evidence for a dramatic surge in star birth in a newly discovered population of massive galaxies in the early Universe. Their measurements confirm the idea that stars formed most rapidly about 11 billion years ago, or about three billion years after the Big Bang, and that the rate of star formation is much faster than was thought.


The scientists used the European Space Agency's Herschel Space Observatory, an infrared telescope carrying the largest mirror ever launched into space. They studied the distant objects in detail with the Spectral and Photometric Imaging Receiver (SPIRE) camera, obtaining solid evidence that the galaxies are forming stars at a tremendous rate and have large reservoirs of gas that will power the star formation for hundreds of millions of years. Their observations also confirm that these galaxies represent a crucial episode in the build up of large galaxies around us today, such as our own Milky Way.

Dr. Scott Chapman, from the Institute of Astronomy in Cambridge, has presented the new results in a paper in a special edition of the journal Monthly Notices of the Royal Astronomical Society focusing on results from Herschel.

Scott comments "These Herschel-SPIRE measurements have revealed the new population of galaxies to be hotter than expected, due to stars forming far much more rapidly than we previously believed."

The galaxies are so distant that the light we detect from them has been travelling for more than 11 billion years. This means that we see them as they were about three billion years after the Big Bang. The key to the new results is the recent discovery of a new type of extremely luminous galaxy in the early Universe. These galaxies are very faint in visible light, as the newly-formed stars are still cocooned in the clouds of gas and dust within which they were born. This cosmic dust, which has a temperature of around -240 degrees C, is much brighter at the longer, far infrared wavelengths observed by the Herschel satellite.

Herschel SPIRE image of galaxies
Credit: ESA/SPIRE/HerMES
Hi-Res Image

A related type of galaxy was first found in 1997 (but not well understood until 2003) using the "SCUBA" camera attached to the James Clerk Maxwell Telescope on Hawaii, which detects radiation emitted at even longer submillimeter wavelengths. But these distant "submillimeter galaxies" were thought to only represent half the picture of star formation in the early Universe. Since SCUBA preferentially detects colder objects, it was suggested that similar galaxies with slightly warmer temperatures could exist but have gone largely unnoticed.

Dr. Chapman and others measured their distances using the Keck optical telescope on Hawaii and the Plateau de Bure submillimeter observatory in France, but were unable to show that they were in the throes of rapid star formation.

The new galaxies have prodigious rates of star formation, far higher than anything seen in the present-day Universe. They probably developed through violent encounters between hitherto undisturbed galaxies, after the first stars and galaxy fragments had already formed. None the less, studying these new objects gives astronomers an insight into the earliest epochs of star formation after the Big Bang.

Team colleague Dr. Isaac Roseboom from the University of Sussex sums up the work. "It was amazing and surprising to see the Herschel-SPIRE observations uncover such a dramatic population of previously unseen galaxies". Professor Seb Oliver, also from Sussex, adds: "We are really blown away by the tremendous capability of Herschel to probe the distant universe. This work by Scott Chapman gives us a real handle on how the cosmos looked early in its life."

With the new discovery, the UK-led astronomers have provided a much more accurate census of some of the most extreme galaxies in the Universe at the peak of their activity. Future observations will investigate the details of the galaxies' power source and try to establish how they will develop once their intense bursts of activity come to an end.

A Galaxy for Everyone

To celebrate the one-year anniversary of the launch of NASA's Wide-Field Infrared Explorer, or WISE, the mission team has put together this image showing just a sample of the millions of galaxies that have been imaged by WISE during its survey of the entire sky. Image credit: NASA/JPL-Caltech/UCLA. Full image and caption

This collage of galaxies from NASA's Wide-Field Infrared Survey Explorer, or WISE, showcases the many "flavors" that galaxies come in, from star-studded spirals to bulging ellipticals to those paired with other companion galaxies. The WISE team put this collage together to celebrate the anniversary of the mission's launch on Dec. 14, 2009.

After launch and a one-month checkout period, WISE began mapping the sky in infrared light. By July of this year, the entire sky had been surveyed, detecting hundreds of millions of objects, including the galaxies pictured here. In October of this year, after scanning the sky about one-and–a-half times, the spacecraft ran out of its frozen coolant, as planned. With its two shortest-wavelength infrared detectors still operational, the mission continues to survey the sky, focusing primarily on asteroids and comets.

NGC 300 is seen in the image in the upper left panel. This is a textbook spiral galaxy. In fact, it is such a good representation of a spiral galaxy that astronomers have studied it in great detail to learn about the structure of all spirals in general. Infrared images like this one from WISE show astronomers where areas of gas and warm dust are concentrated -- features that cannot be seen in visible light. At about 39,000 light-years across, NGC 300 is only about 40 percent the size of the Milky Way galaxy.

The upper right image shows Messier 104, or M104, also known as the Sombrero galaxy. Although M104 is also classified as a spiral galaxy, it has a very different appearance than NGC 300. In part, this is because the dusty, star-forming spiral disk in M104 is seen nearly edge-on from our point of view. M104 also has a large, ball-shaped bulge component of older stars, seen here in blue.

The large, fuzzy grouping of stars at the center of the lower left panel is the galaxy Messier 60, or M60. This galaxy does not have a spiral disk, just a bulge, making it a massive elliptical galaxy. M60 is about 20 percent larger than our Milky Way galaxy, and lies in the Virgo cluster of galaxies. The brighter, dense spot inside but off-center from the blue core of M60 is a separate spiral galaxy called NGC 4647. In addition, two different asteroids were caught crossing the field of view when WISE imaged this portion of the sky (seen as dotted green lines extending out from M60 at about the 2 o'clock and 8 o'clock positions).

The galaxy in the lower right panel is Messier 51, or NGC 5194, also frequently referred to as the Whirlpool galaxy. The Whirlpool is a "grand design" spiral galaxy. It is interacting with its smaller companion -- NGC 5195, a dwarf galaxy, which can be seen as a bright spot near the tip of the spiral arm extending up and to the right of the Whirlpool galaxy.

JPL manages and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise .

Whitney Clavin (818) 354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

Thursday, December 16, 2010

Light Dawns on Dark Gamma-ray Bursts

PR Image eso1049a
Artist's impression of a dark gamma-ray burst

ESOcast 25: Chasing Gamma Ray Bursts at Top Speed
The VLT’s Rapid Response Mode

Gamma-ray bursts are among the most energetic events in the Universe, but some appear curiously faint in visible light. The biggest study to date of these so-called dark gamma-ray bursts, using the GROND instrument on the 2.2-metre MPG/ESO telescope at La Silla in Chile, has found that these gigantic explosions don’t require exotic explanations. Their faintness is now fully explained by a combination of causes, the most important of which is the presence of dust between the Earth and the explosion.

Gamma-ray bursts (GRBs), fleeting events that last from less than a second to several minutes, are detected by orbiting observatories that can pick up their high energy radiation. Thirteen years ago, however, astronomers discovered a longer-lasting stream of less energetic radiation coming from these violent outbursts, which can last for weeks or even years after the initial explosion. Astronomers call this the burst’s afterglow.

While all gamma-ray bursts [1] have afterglows that give off X-rays, only about half of them were found to give off visible light, with the rest remaining mysteriously dark. Some astronomers suspected that these dark afterglows could be examples of a whole new class of gamma-ray bursts, while others thought that they might all be at very great distances. Previous studies had suggested that obscuring dust between the burst and us might also explain why they were so dim.

“Studying afterglows is vital to further our understanding of the objects that become gamma-ray bursts and what they tell us about star formation in the early Universe,” says the study’s lead author Jochen Greiner from the Max-Planck Institute for Extraterrestrial Physics in Garching bei München, Germany.

NASA launched the Swift satellite at the end of 2004. From its orbit above the Earth’s atmosphere it can detect gamma-ray bursts and immediately relay their positions to other observatories so that the afterglows could be studied. In the new study, astronomers combined Swift data with new observations made using GROND [2] — a dedicated gamma-ray burst follow-up observation instrument, which is attached to the 2.2-metre MPG/ESO telescope at La Silla in Chile. In doing so, astronomers have conclusively solved the puzzle of the missing optical afterglow.

What makes GROND exciting for the study of afterglows is its very fast response time — it can observe a burst within minutes of an alert coming from Swift using a special system called the Rapid Response Mode — and its ability to observe simultaneously through seven filters covering both the visible and near-infrared parts of the spectrum.

By combining GROND data taken through these seven filters with Swift observations, astronomers were able to accurately determine the amount of light emitted by the afterglow at widely differing wavelengths, all the way from high energy X-rays to the near-infrared. The astronomers used this information to directly measure the amount of obscuring dust that the light passed through en route to Earth. Previously, astronomers had to rely on rough estimates of the dust content [3].

The team used a range of data, including their own measurements from GROND, in addition to observations made by other large telescopes including the ESO Very Large Telescope, to estimate the distances to nearly all of the bursts in their sample. While they found that a significant proportion of bursts are dimmed to about 60–80 percent of the original intensity by obscuring dust, this effect is exaggerated for the very distant bursts, letting the observer see only 30–50 percent of the light [4]. The astronomers conclude that most dark gamma-ray bursts are therefore simply those that have had their small amount of visible light completely stripped away before it reaches us.

“Compared to many instruments on large telescopes, GROND is a low cost and relatively simple instrument, yet it has been able to conclusively resolve the mystery surrounding dark gamma-ray bursts,” says Greiner.

Notes

[1] Gamma-ray bursts lasting longer than two seconds are referred to as long bursts and those with a shorter duration are known as short bursts. Long bursts, which were observed in this study, are associated with the supernova explosions of massive young stars in star-forming galaxies. Short bursts are not well understood, but are thought to originate from the merger of two compact objects such as neutron stars.

[2] The Gamma-Ray burst Optical and Near-infrared Detector (GROND) was designed and built at the Max-Planck Institute for Extraterrestrial Physics in collaboration with the Tautenburg Observatory, and has been fully operational since August 2007.

[3] Other studies relating to dark gamma-ray bursts have been released. Early this year, astronomers used the Subaru Telescope to observe a single gamma-ray burst, from which they hypothesised that dark gamma-ray bursts may indeed be a separate sub-class that form through a different mechanism, such as the merger of binary stars. In another study published last year using the Keck Telescope, astronomers studied the host galaxies of 14 dark GRBs, and based on the derived low redshifts they infer dust as the likely mechanism to create the dark bursts. In the new work reported here, 39 GRBs were studied, including nearly 20 dark bursts, and it is the only study in which no prior assumptions have been made and the amount of dust has been directly measured.

[4] Because the afterglow light of very distant bursts is redshifted due to the expansion of the Universe, the light that left the object was originally bluer than the light we detect when it gets to Earth. Since the reduction of light intensity by dust is greater for blue and ultraviolet light than for red, this means that the overall dimming effect of dust is greater for the more distant gamma-ray bursts. This is why GROND’s ability to observe near-infrared radiation makes such a difference.

More information

This research is presented in a paper to appear in the journal Astronomy & Astrophysics on 16 December 2010

The team is composed of: J. Greiner (Max-Planck-Institut für extraterrestrische Physik [MPE], Germany), T. Krühler (MPE, Universe Cluster, Technische Universität München), S. Klose (Thüringer Landessternwarte, Germany), P. Afonso (MPE), C. Clemens (MPE), R. Filgas (MPE), D.H. Hartmann (Clemson University, USA), A. Küpcü Yoldaş¸ (University of Cambridge, UK), M. Nardini (MPE), F. Olivares E. (MPE), A. Rau (MPE), A. Rossi (Thüringer Landessternwarte, Germany), P. Schady (MPE), and A. Updike (Clemson University, USA)

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and VISTA, the world’s largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links

Research paper in A&A
GROND website
Photos of the La Silla Observatory
Photo of MPG/ESO 2.2-metre telescope


Contacts

Jochen Greiner
Max-Planck Institute for Extraterrestrial Physics
Garching bei München, Germany
Tel: +49 89 30000 3847
Email: jcg@mpe.mpg.de

Richard Hook
ESO, La Silla, Paranal, E-ELT and Survey Telescopes Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Wednesday, December 15, 2010

Building Blocks of Life Created in "Impossible" Place

This is a NASA Hubble Space Telescope picture of what was first thought to be a comet but is probably an asteroid collision. The inset picture shows a complex structure that suggests the object is not a comet but instead the product of a head-on collision between two asteroids traveling five times faster than a rifle bullet (about three miles per second). Astronomers have long thought that the asteroid belt is being ground down through collisions, but such a smashup has never before been seen. The filaments are made of dust and gravel, presumably recently thrown out of the 460-foot-diameter nucleus. Some of the filaments are swept back by radiation pressure from sunlight to create straight dust streaks. Embedded in the filaments are co-moving blobs of dust that likely originate from tiny unseen parent bodies. An impact origin would also be consistent with the absence of gas in spectra recorded using ground-based telescopes. At the time of the Hubble observations in January 2010, the object was approximately 180 million miles (300 million km) from the Sun and 90 million miles (140 million km) from Earth. Credit: NASA, ESA, and D. Jewitt (UCLA). Full-resolution copy

GREENBELT, Md. -- NASA-funded scientists have discovered amino acids, a fundamental building block of life, in a meteorite where none were expected.

"This meteorite formed when two asteroids collided," said Dr. Daniel Glavin of NASA’s Goddard Space Flight Center, Greenbelt, Md. "The shock of the collision heated it to more than 2,000 degrees Fahrenheit, hot enough that all complex organic molecules like amino acids should have been destroyed, but we found them anyway." Glavin is lead author of a paper on this discovery appearing December 15 in Meteoritics and Planetary Science. "Finding them in this type of meteorite suggests that there is more than one way to make amino acids in space, which increases the chance for finding life elsewhere in the Universe."

Amino acids are used to make proteins, the workhorse molecules of life, used in everything from structures like hair to enzymes, the catalysts that speed up or regulate chemical reactions. Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins. Previously, scientists at the Goddard Astrobiology Analytical Laboratory have found amino acids in samples of comet Wild 2 from NASA’s Stardust mission, and in various carbon-rich meteorites. Finding amino acids in these objects supports the theory that the origin of life got a boost from space -- some of life’s ingredients formed in space and were delivered to Earth long ago by meteorite impacts.

When Dr. Peter Jenniskens of the SETI Institute, Mountain View, Calif., and NASA's Ames Research Center, Moffett Field, Calif., approached NASA with the suggestion to search for amino acids in the carbon-rich remnants of asteroid 2008 TC3, expectations were that nothing was to be found. Because of an unusually violent collision in the past, this asteroid's ingredients for life were a "culinary disaster" and now mostly in the form of graphite. The small asteroid, estimated at six to fifteen feet across, was the first to be detected in space prior to impact on Earth on October 7, 2008. When Jenniskens and Dr. Muawia Shaddad of the University of Khartoum recovered remnants in the Nubian Desert of northern Sudan, the remnants turned out to be the first Ureilite meteorites found in pristine condition.

A meteorite sample was divided between the Goddard lab and a lab at the Scripps Institution of Oceanography at the University of California, San Diego. "Our analyses confirm those obtained at Goddard," said Professor Jeffrey Bada of Scripps, who led the analysis there. The extremely sensitive equipment in both labs detected small amounts of 19 different amino acids in the sample, ranging from 0.5 to 149 parts per billion. The team had to be sure that the amino acids in the meteorite didn’t come from contamination by life on Earth, and they were able to do so because of the way amino acids are made. Amino acid molecules can be built in two ways that are mirror images of each other, like your hands. Life on Earth uses left-handed amino acids, and they are never mixed with right-handed ones, but the amino acids found in the meteorite had equal amounts of the left and right-handed varieties.

The sample had various minerals that only form under high temperatures, indicating it was forged in a violent collision. It's possible that the amino acids are simply leftovers from one of the original asteroids in the collision – an asteroid that had better conditions for amino acid formation. Dr. Jennifer Blank of SETI has done experiments with amino acids in water and ice, showing they survive pressures and temperatures comparable to a low-angle comet-Earth impact or asteroid-asteroid collisions.

However, the team thinks it's unlikely amino acids could have survived the conditions that created the meteorite, which endured higher temperatures – more than 2,000 degrees Fahrenheit (over 1,100 Celsius) – over a much longer period. "It would be hard to transfer amino acids from an impactor to another body simply because of the high-energy conditions associated with the impact," said Bada.

Instead, the team believes there’s an alternate method for making amino acids in space. "Previously, we thought the simplest way to make amino acids in an asteroid was at cooler temperatures in the presence of liquid water. This meteorite suggests there’s another way involving reactions in gases as a very hot asteroid cools down," said Glavin. The team is planning experiments to test various gas-phase chemical reactions to see if they generate amino acids.

Infrared image taken by the Meteosat 8 satellite of asteroid 2008 TC3 exploding. The path of the asteroid is shown with a yellow arrow; red-yellow blob on arrow is infrared from the explosion. Credit: EUMESTAT

A typical example of a meteorite remnant linked to asteroid 2008 TC3, with a dark scruffy texture. Credit: Peter Jenniskens. Full-resolution copy

Fragments of 2008 TC3 are collectively called "Almahata Sitta" or "Station Six" after the train stop in northern Sudan near the location where pieces were recovered. They are prized because they are Ureilites, a rare type of meteorite. "An interesting possibility is that Ureilites are thought by some researchers to have formed in the solar nebula and thus the findings of amino acids in Almahata Sitta might imply that amino acids were in fact synthesized very early in the history of the solar system," adds Bada.

The Goddard analysis team includes Glavin and Drs. Jason Dworkin, Michael Callahan, and Jamie Elsila. This research was funded by the NASA Astrobiology Institute, which is managed by NASA Ames; the Goddard Center for Astrobiology, and the NASA Cosmochemistry and Astrobiology: Exobiology and Evolutionary Biology programs.

Contact

Nancy Neal-Jones / Bill Steigerwald
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-286-0039 / 5017
Nancy.N.Jones@nasa.gov / William.A.Steigerwald@nasa.gov

Hot Plasma Explosions Inflate Saturn's Magnetic Field

This is an artist's concept of the Saturnian plasma sheet based on data from Cassini magnetospheric imaging instrument. Image credit: NASA/JPL/JHUAPL. Full image and caption

This is an artist's concept of the Saturnian plasma sheet based on data from Cassini magnetospheric imaging instrument. It shows Saturn's embedded "ring current," an invisible ring of energetic ions trapped in the planet's magnetic field. Full image and caption

A new analysis based on data from NASA's Cassini spacecraft finds a causal link between mysterious, periodic signals from Saturn's magnetic field and explosions of hot ionized gas, known as plasma, around the planet.

Scientists have found that enormous clouds of plasma periodically bloom around Saturn and move around the planet like an unbalanced load of laundry on spin cycle. The movement of this hot plasma produces a repeating signature "thump" in measurements of Saturn's rotating magnetic environment and helps to illustrate why scientists have had such a difficult time measuring the length of a day on Saturn.

"This is a breakthrough that may point us to the origin of the mysteriously changing periodicities that cloud the true rotation period of Saturn," said Pontus Brandt, the lead author on the paper and a Cassini team scientist based at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The big question now is why these explosions occur periodically."
The data show how plasma injections, electrical currents and Saturn's magnetic field -- phenomena that are invisible to the human eye -- are partners in an intricate choreography. Periodic plasma explosions form islands of pressure that rotate around Saturn. The islands of pressure "inflate" the magnetic field.

A new animation showing the linked behavior is available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

The visualization shows how invisible hot plasma in Saturn's magnetosphere – the magnetic bubble around the planet -- explodes and distorts magnetic field lines in response to the pressure. Saturn's magnetosphere is not a perfect bubble because it is blown back by the force of the solar wind, which contains charged particles streaming off the sun.

The force of the solar wind stretches the magnetic field of the side of Saturn facing away from the sun into a so-called magnetotail. The collapse of the magnetotail appears to kick off a process that causes the hot plasma bursts, which in turn inflate the magnetic field in the inner magnetosphere.

Scientists are still investigating what causes Saturn's magnetotail to collapse, but there are strong indications that cold, dense plasma originally from Saturn's moon Enceladus rotates with Saturn. Centrifugal forces stretch the magnetic field until part of the tail snaps back.

The snapping back heats plasma around Saturn and the heated plasma becomes trapped in the magnetic field. It rotates around the planet in islands at the speed of about 100 kilometers per second (200,000 mph). In the same way that high and low pressure systems on Earth cause winds, the high pressures of space cause electrical currents. Currents cause magnetic field distortions.

A radio signal known as Saturn Kilometric Radiation, which scientists have used to estimate the length of a day on Saturn, is intimately linked to the behavior of Saturn's magnetic field. Because Saturn has no surface or fixed point to clock its rotation rate, scientists inferred the rotation rate from timing the peaks in this type of radio emission, which is assumed to surge with each rotation of a planet. This method has worked for Jupiter, but the Saturn signals have varied. Measurements from the early 1980s taken by NASA's Voyager spacecraft, data obtained in 2000 by the ESA/NASA Ulysses mission, and Cassini data from about 2003 to the present differ by a small, but significant degree. As a result, scientists are not sure how long a Saturn day is.

"What's important about this new work is that scientists are beginning to describe the global, causal relationships between some of the complex, invisible forces that shape the Saturn environment," said Marcia Burton, the Cassini fields and particles investigation scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The new results still don't give us the length of a Saturn day, but they do give us important clues to begin figuring it out. The Saturn day length, or Saturn's rotation rate, is important for determining fundamental properties of Saturn, like the structure of its interior and the speed of its winds."

Plasma is invisible to the human eye. But the ion and neutral camera on Cassini's magnetospheric imaging instrument provides a three-dimensional view by detecting energetic neutral atoms emitted from the plasma clouds around Saturn. Energetic neutral atoms form when cold, neutral gas collides with electrically-charged particles in a cloud of plasma. The resulting particles are neutrally charged, so they are able to escape magnetic fields and zoom off into space. The emission of these particles often occurs in the magnetic fields surrounding planets.

By stringing together images obtained every half hour, scientists produced movies of plasma as it drifted around the planet. Scientists used these images to reconstruct the 3-D pressure produced by the plasma clouds, and supplemented those results with plasma pressures derived from the Cassini plasma spectrometer. Once scientists understood the pressure and its evolution, they could calculate the associated magnetic field perturbations along the Cassini flight path. The calculated field perturbation matched the observed magnetic field "thumps" perfectly, confirming the source of the field oscillations.

"We all know that changing rotation periods have been observed at pulsars, millions of light years from our solar system, and now we find that a similar phenomenon is observed right here at Saturn," said Tom Krimigis, principal investigator of the magnetospheric imaging instrument, also based at the Applied Physics Laboratory and the Academy of Athens, Greece. "With instruments right at the spot where it's happening, we can tell that plasma flows and complex current systems can mask the real rotation period of the central body. That's how observations in our solar system help us understand what is seen in distant astrophysical objects."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif. manages the mission for NASA's Science Mission Directorate, Washington, D.C. The magnetic imaging instrument team is based at the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini .

Jia-Rui Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Tuesday, December 14, 2010

Qatar-Led International Team Finds Their First Alien World

The newly-discovered alien world Qatar-1b orbits an orange type K star 550 light-years from Earth. Qatar-1b is a gas giant 20 percent larger than Jupiter in diameter and 10 percent more massive. It circles its star once every 1.4 days, meaning that its "year" is just 34 hours long. Credit: David A. Aguilar (CfA). High Resolution Image (jpg)

Cambridge, MA - In an exciting example of international collaboration, a Qatar astronomer teamed with scientists at the Harvard-Smithsonian Center for Astrophysics (CfA) and other institutions to discover a new alien world. This "hot Jupiter," now named Qatar-1b, adds to the growing list of alien planets orbiting distant stars. Its discovery demonstrates the power of science to cross political boundaries and increase ties between nations.

"The discovery of Qatar-1b is a great achievement -- one that further demonstrates Qatar's commitment to becoming a leader in innovative science and research," said Dr. Khalid Al Subai, leader of the Qatar exoplanet survey and a research director of the Qatar Foundation for Education, Science and Community Development.

"This discovery marks the beginning of a new era of collaborative astrophysics research between Qatar, the United Kingdom, and the United States," he added.

The Qatar exoplanet survey hunts for stars that "wink," dimming slightly every time an orbiting planet creates a "mini-eclipse" by crossing in front of the star as seen from Earth. Transit searches like this must sift through thousands of stars to find the small fraction with detectable planets. The complex observations and analysis create perfect opportunities for teamwork.

"The discovery of Qatar-1b is a wonderful example of how science and modern communications can erase international borders and time zones. No one owns the stars. We can all be inspired by the discovery of distant worlds," said CfA team member David Latham.

To find the new world, Qatar's wide-angle cameras (located in New Mexico) took images of the sky every clear night beginning in early 2010. The photographs then were transmitted to the UK for analysis by collaborating astronomers at St. Andrews and Leicester Universities and Qatar. That analysis narrowed the field to a few hundred candidate stars.

The Harvard-Smithsonian team, with Dr. Al Subai, followed up on the most promising candidates, making spectroscopic observations with the 60-inch-diameter telescope at the Smithsonian's Whipple Observatory in Arizona. Such observations can weed out binary-star systems with grazing eclipses, which mimic planetary transits. They also measured the stars' dimming more accurately with Whipple's 48-inch telescope.

The resulting data confirmed the existence of a planet now called Qatar-1b, orbiting an orange Type K star 550 light-years away. Qatar-1b is a gas giant 20 percent larger than Jupiter in diameter and 10 percent more massive. It belongs to the "hot Jupiter" family because it orbits 2.2 million miles from its star - only six stellar radii away. The planet roasts at a temperature of around 2,000 degrees Fahrenheit.

Qatar-1b circles its star once every 1.4 days, meaning that its "year" is just 34 hours long. It's expected to be tidally locked with the star, so one side of the planet always faces the star. As a result, the planet spins on its axis once every 34 hours - three times slower than Jupiter, which rotates once in 10 hours.

A paper announcing this discovery has been submitted to the Monthly Notices of the Royal Astronomical Society for publication.

More information is available at www.alsubaiproject.org.

For a complete list of the Qatar Foundation's initiatives and projects, visit http://www.qf.org.qa.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

For more information, contact:

David A. Aguilar
Director of Public Affairs
Harvard-Smithsonian Center for Astrophysics
617-495-7462
daguilar@cfa.harvard.edu

Christine Pulliam
Public Affairs Specialist
Harvard-Smithsonian Center for Astrophysics
617-495-7463
cpulliam@cfa.harvard.edu

Riham El-Houshi
Qatar Foundation
974-3318-0096
relhoushi@qf.org.qa

Hubble spots a celestial bauble

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Hubble spots a celestial bauble

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Hubble and Chandra spot a celestial bauble

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Hubble spots a celestial bauble

Hubble has spotted a festive bauble of gas in our neighbouring galaxy, the Large Magellanic Cloud. Formed in the aftermath of a supernova explosion that took place four centuries ago, this sphere of gas has been snapped in a series of observations made between 2006 and 2010.

The delicate shell, photographed by the NASA/ESA Hubble Space Telescope, appears to float serenely in the depths of space, but this apparent calm hides an inner turmoil. The gaseous envelope formed as the expanding blast wave and ejected material from a supernova tore through the nearby interstellar medium. Called SNR B0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160 000 light-years from Earth.

Ripples seen in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or possibly be driven from the interior by fragments from the initial explosion. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Astronomers have concluded that the explosion was an example of an especially energetic and bright variety of supernova. Known as Type Ia, such supernova events are thought to result when a white dwarf star in a binary system robs its partner of material, taking on more mass than it is able to handle, so that it eventually explodes.

Hubble’s Advanced Camera for Surveys observed the supernova remnant on 28 October 2006 with a filter that isolates light from the glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble’s Wide Field Camera 3 on 4 November 2010.

With an age of about 400 years, the supernova might have been visible to southern hemisphere observers around the year 1600, although there are no known records of a “new star” in the direction of the LMC near that time. A much more recent supernova in the LMC, SN 1987A, did catch the eye of Earth viewers and continues to be studied with ground- and space-based telescopes, including Hubble.

Notes

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgement: J. Hughes (Rutgers University)

Links

Images of Hubble
NASA HubbleSite release
NASA: NASA Hubble Heritage release

Contacts

Oli Usher
Hubble/ESA
Garching, Germany
Tel: +49-89-3200-6855
Email: ousher@eso.org

Ray Villard
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-4514
Email: villard@stsci.edu

Keith Noll
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-1828
Email: noll@stsci.edu

NASA Probe Sees Solar Wind Decline

Artist concept of Voyager near interstellar space.
Image credit: NASA/JPL
Learn more about the terms used

PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has reached a distant point at the edge of our solar system where there is no outward motion of solar wind.

Now hurtling toward interstellar space some 17.4 billion kilometers (10.8 billion miles) from the sun, Voyager 1 has crossed into an area where the velocity of the hot ionized gas, or plasma, emanating directly outward from the sun has slowed to zero. Scientists suspect the solar wind has been turned sideways by the pressure from the interstellar wind in the region between stars.

The event is a major milestone in Voyager 1's passage through the heliosheath, the turbulent outer shell of the sun's sphere of influence, and the spacecraft's upcoming departure from our solar system.

"The solar wind has turned the corner," said Ed Stone, Voyager project scientist based at the California Institute of Technology in Pasadena, Calif. "Voyager 1 is getting close to interstellar space."

Our sun gives off a stream of charged particles that form a bubble known as the heliosphere around our solar system. The solar wind travels at supersonic speed until it crosses a shockwave called the termination shock. At this point, the solar wind dramatically slows down and heats up in the heliosheath.

Launched on Sept. 5, 1977, Voyager 1 crossed the termination shock in December 2004 into the heliosheath. Scientists have used data from Voyager 1's Low-Energy Charged Particle Instrument to deduce the solar wind's velocity. When the speed of the charged particles hitting the outward face of Voyager 1 matched the spacecraft's speed, researchers knew that the net outward speed of the solar wind was zero. This occurred in June, when Voyager 1 was about 17 billion kilometers (10.6 billion miles) from the sun.

Because the velocities can fluctuate, scientists watched four more monthly readings before they were convinced the solar wind's outward speed actually had slowed to zero. Analysis of the data shows the velocity of the solar wind has steadily slowed at a rate of about 20 kilometers per second each year (45,000 mph each year) since August 2007, when the solar wind was speeding outward at about 60 kilometers per second (130,000 mph). The outward speed has remained at zero since June.

The results were presented today at the American Geophysical Union meeting in San Francisco.

"When I realized that we were getting solid zeroes, I was amazed," said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and senior staff scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "Here was Voyager, a spacecraft that has been a workhorse for 33 years, showing us something completely new again."

Scientists believe Voyager 1 has not crossed the heliosheath into interstellar space. Crossing into interstellar space would mean a sudden drop in the density of hot particles and an increase in the density of cold particles. Scientists are putting the data into their models of the heliosphere's structure and should be able to better estimate when Voyager 1 will reach interstellar space. Researchers currently estimate Voyager 1 will cross that frontier in about four years.

"In science, there is nothing like a reality check to shake things up, and Voyager 1 provided that with hard facts," said Tom Krimigis, principal investigator on the Low-Energy Charged Particle Instrument, who is based at the Applied Physics Laboratory and the Academy of Athens, Greece. "Once again, we face the predicament of redoing our models."

A sister spacecraft, Voyager 2, was launched in Aug. 20, 1977 and has reached a position 14.2 billion kilometers (8.8 billion miles) from the sun. Both spacecraft have been traveling along different trajectories and at different speeds. Voyager 1 is traveling faster, at a speed of about 17 kilometers per second (38,000 mph), compared to Voyager 2's velocity of 15 kilometers per second (35,000 mph). In the next few years, scientists expect Voyager 2 to encounter the same kind of phenomenon as Voyager 1.

The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft. For more information about the Voyager spacecraft, visit: http://www.nasa.gov/voyager . JPL is a division of the California Institute of Technology in Pasadena.

Jia-Rui Cook 818-359-3241
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Dwayne Brown 202-358-1726
Headquarters, Washington
dwayne.c.brown@nasa.gov

Sunday, December 12, 2010

Astronomy Without A Telescope – Forbidden Planets

The theorized evolution of the circumbinary planet PSR B1620-26 b. Credit: NASA.

Binary star systems can have planets – although these are generally assumed to be circumbinary (where the orbit encircles both stars). As well as the fictional examples of Tatooine and Gallifrey, there are real examples of PSR B1620-26 b and HW Virginis b and c – thought to be cool gas giants with several times the mass of Jupiter, orbiting several astronomical units out from their binary suns.
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Planets in circumstellar orbits around a single star within a binary system are traditionally considered to be unlikely due to the mathematical implausibility of maintaining a stable orbit through the ‘forbidden’ zones – which result from gravitational resonances generated by the motion of the binary stars. The orbital dynamics involved should either fling a planet out of the system or send it crashing to its doom into one or other of the stars. However, there may be a number of windows of opportunity available for ‘next generation’ planets to form at later stages in the evolving life of a binary system.

A binary stellar evolution scenario might go something like this:

1) You start with two main sequence stars orbiting their common centre of mass. Circumstellar planets may only achieve stable orbits very close in to either star. If present at all, it’s unlikely these planets would be very large as neither star could sustain a large protoplanetary disk given their close proximity.

2) The more massive of the binaries evolves further to become an Asymptotic Giant Branch star (i.e. red giant) – potentially destroying any planets it may have had. Some mass is lost from the system as the red giant blows off its outer layers – which is likely to increase the separation of the two stars. But this also provides material for a protoplanetary disk to form around the red giant’s binary companion star.

3) The red giant evolves into white dwarf, while the other star (still in main sequence and now with extra fuel and a protoplanetary disk) can develop a system of orbiting ‘second generation’ planets. This new stellar system could remain stable for a billion years or more.

4) The remaining main sequence star eventually goes red giant, potentially destroying its planets and further widening the separation of the two stars – but it also may contribute material to form a protoplanetary disk around the distant white dwarf star, providing the opportunity for third generation planets to form there.

How a binary system might give birth to generations of planets: a) First generation planets - small and close-in - might be possible while both stars are on the main sequence (MS) and in close proximity to each other; b) Eventually one star evolves from the main sequence to the Asymptotic Giant Branch (AGB) - in other words, it goes red giant. c) The two stars spread further apart while stellar material blown off from the red giant builds a protoplanetary disk around the other star and second generation planets form; d) the second star eventually goes red giant giving the first star (now a white dwarf - WD) a protoplanetary disk which could create a third generation of planets. Credit: Perets, H.B.

The development of the third generation planetary system depends on the white dwarf star sustaining a mass below its Chandrasekhar limit (being about 1.4 solar masses – depending on its rate of spin) despite it having received more material from the red giant. If it doesn’t stay below that limit, it will become a Type 1a supernova – potentially lobbing a small proportion of its mass back to the other star again, although by this stage that other star would be a very distant companion.

An interesting feature of this evolutionary story is that each generation of planets is built from stellar material with a sequentially increasing proportion of ‘metals’ (elements heavier than hydrogen and helium) as the material is cooked and re-cooked within each stars’ fusion processes. Under this scenario, it becomes feasible for old stars, even those which formed as low metal binaries, to develop rocky planets later in their lifetimes.

Further reading: Perets, H.B. Planets in evolved binary systems.

by Steve Nerlich

Source: Universe Today

Friday, December 10, 2010

WISE Sees an Explosion of Infrared Light

This oddly colorful nebula is the supernova remnant IC 443 as seen by NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA. Full image and caption

A circular rainbow appears like a halo around an exploded star in this new view of the IC 443 nebula from NASA's Wide-field Infrared Survey Explorer, or WISE.

When massive stars die, they explode in tremendous blasts, called supernovae, which send out shock waves. The shock waves sweep up and heat surrounding gas and dust, creating supernova remnants like the one pictured here. The supernova in IC 443 happened somewhere between 5,000 and 10,000 years ago.

In this WISE image, infrared light has been color-coded to reveal what our eyes cannot see. The colors differ primarily because materials surrounding the supernova remnant vary in density. When the shock waves hit these materials, different gases were triggered to release a mix of infrared wavelengths.

The supernova remnant's northeastern shell, seen here as the violet-colored semi-circle at top left, is composed of sheet-like filaments that are emitting light from iron, neon, silicon and oxygen gas atoms and dust particles heated by a fast shock wave traveling at about 100 kilometers per second, or 223,700 mph.

The smaller southern shell, seen in bright bluish colors, is constructed of clumps and knots primarily emitting light from hydrogen gas and dust heated by a slower shock wave traveling at about 30 kilometers per second, or 67,100 miles per hour. In the case of the southern shell, the shock wave is interacting with a nearby dense cloud. This cloud can be seen in the image as the greenish dust cutting across IC 443 from the northwest to southeast.

IC 443 can be found near the star Eta Geminorum, which lies near Castor, one of the twins in the constellation Gemini.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise .

Whitney Clavin (818) 354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov

Thursday, December 09, 2010

Black holes and warped space: New UK telescope shows off first images

Composite of the new e-MERLIN radio image of the Double Quasar and an earlier HST optical image. Credit: Jodrell Bank, University of Manchester

This dramatic image is the first to be produced by e-MERLIN, a powerful new array of radio telescopes linked across the UK.

Spearheaded by the University of Manchester’s Jodrell Bank Observatory and funded by the Science and Technology Facilities Council, the e-MERLIN telescope will allow astronomers to address key questions relating to the origin and evolution of galaxies, stars and planets.

To demonstrate its capabilities, University of Manchester astronomers turned the new telescope array toward the 'Double Quasar'. This enigmatic object, first discovered by Jodrell Bank, is a famous example of Einstein’s theory of gravity in action.

The new image shows how the light from a quasar billions of light years away is bent around a foreground galaxy by the curvature of space. This light has been travelling for 9 billion years before it reached the Earth. The quasar is a galaxy powered by a super-massive black hole, leading to the ejection of jets of matter moving at almost the speed of light – one of which can be seen arcing to the left in this new e-MERLIN image.

The warping of space results in a 'gravitational lens' producing multiple images of the same quasar – the two brightest of these lensed images can be seen here as two bright objects, one below the other. The foreground galaxy whose mass is responsible for the lensing effect is also visible just above the lower quasar image. The radio emission seen in the e-MERLIN image suggests that this galaxy also harbours a black hole, albeit somewhat smaller.

The UK's national facility for radio astronomy, e-MERLIN is now set to produce increasingly-detailed radio images of stars and galaxies using seven telescopes spread up to 220 km apart across the UK and working as one. This combination of widely-spread telescopes provides astronomers with a powerful 'zoom lens' with which they can study the fine details of astronomical events out towards the edge of the observable universe.

The radio signals collected by the telescopes are brought back to Jodrell Bank using a new optical fibre network. These fibre links and advanced electronic receivers will allow astronomers to collect far more data and so see in a single day what would have previously taken them more than a year of observations.

Whole field of view of the Double Quasar, as seen by e-MERLIN alone Credit: Jodrell Bank, University of Manchester

In parallel with this successful demonstration of the new telescope system, work has begun on 'early science' observations intended to rigorously test its capabilities. The project has attracted astronomers from over 100 institutes across the world who will use e-MERLIN to study a huge range of astrophysics. This includes star birth and death, black holes and galaxy evolution, pulsars (the collapsed cores of exploded stars) and young planets forming around nearby stars.

The e-MERLIN project has been funded by STFC, the Northwest Development Agency, The University of Manchester, The University of Cambridge and Liverpool John Moores University. It is being operated by STFC and the University of Manchester.

Minister for Science and Universities, David Willetts said: "The image produced by the e-Merlin telescope is inspiring to all with an interest in the space sector.

"I am confident this impressive project will reap significant scientific rewards - it demonstrates how effective British universities are in this field."

Professor Simon Garrington, Director of e-MERLIN at the University of Manchester, says "This first image demonstrates the success of the complex new system of electronics and optical fibre links.

"It is also testament to the hard work put in by our engineers, scientists and technicians to turn our vision of a huge fibre-connected array of telescopes into a reality. We are very much looking forward to the new scientific results that will flow from the telescope over the coming years."

STFC's Professor John Womersley said, "e-Merlin is a flagship project for the UK in radio astronomy, a scientific field where the UK has a rich legacy, a strong future, and is proud to be the home of some of the very best researchers in the world.

"The project has attracted more than 300 astronomers from over 100 institutes in more than 20 countries who will use the power of this ‘super telescope’ to conduct major scientific legacy projects."

Professor Mike Garrett, General Director of ASTRON, the Netherlands Institute for Radio Astronomy, said "e-MERLIN is going to be a transformational telescope – astronomers around the world can't wait to get their hands on it.

"As a pathfinder for the next-generation international radio telescope, the Square Kilometre Array, e-MERLIN represents another giant leap forward for the global radio astronomy community."

Further information Images and an animation are available from the Jodrell Bank website .

Contacts

Bekky Stredwick
Press Office
STFC Rutherford Appleton Laboratory

Tel: +44 (0)1235 861 436

Mob: +44 (0)7825 861 436


Dan Cochlin
Media Relations
The University of Manchester

Tel: +44 (0)161 275 8387


Further quotes

Professor Steve Watts, Head of the University of Manchester’s School of Physics & Astronomy (of which Jodrell Bank Observatory is a part), says: "The development of this groundbreaking new telescope follows more than 60 years of radio astronomy research and development at Jodrell Bank Observatory. Our astronomers will be working closely with colleagues from around the world to make new scientific discoveries with e-MERLIN."

Professor Steve Rawlings of the University of Oxford says "This is a fantastic image. Nature provides us with gravitational lenses that help us study black holes across the Universe, but it is talented engineers and scientists that develop the technologies and instruments that allow us to exploit them. It's great for the UK that the e-MERLIN team are such world leaders in radio astronomy."


Dr Neal Jackson of the University of Manchester, an expert in gravitational lensing, says "This first image of the Double Quasar clearly demonstrates how useful e-MERLIN is going to be in our studies of gravitational lenses. By mapping the bending of light by mass we will be able to study the way in which both stars and dark matter are distributed in galaxies and how this changes as the universe evolves."


e-MERLIN

e-MERLIN (link opens in a new window) is an array of seven radio telescopes across the UK whose signals are brought back on an optical fibre network to The University of Manchester’s Jodrell Bank Observatory. Here they are combined in a highly-specialised supercomputer called a correlator (designed and constructed by the Dominion Radio Astrophysical Observatory of the National Research Council of Canada). The telescope array can then operate as a dedicated radio interferometer to produce high-resolution images. With a maximum baseline length of 220 km, e-MERLIN provides a unique capability for radio imaging with 0.01-0.15-arcsec resolution at wide bands around frequencies of 1.5, 5 and 22 GHz (L, C and K bands).

e-MERLIN is the UK's national facility for high resolution radio astronomy and is operated by The University of Manchester and the Science and Technology Facilities Council.


The e-MERLIN upgrade has been funded by the Science and Technology Facilities Council (STFC), the Northwest Development Agency, The University of Manchester, The University of Cambridge and Liverpool John Moores University. It is being operated by STFC and the University of Manchester.


The Double Quasar image


The 'Double Quasar' is a gravitational lens – a famous confirmation of Albert Einstein’s General Theory of Relativity showing that mass causes space to be curved.
For a detailed summary of the Double Quasar, all images and an animation please visit the Jodrell Bank website .

About SFC

Wednesday, December 08, 2010

Keck Observatory Pictures Show Fourth Planet in Giant Solar System

Infrared image of the HR8799 planetary system. This image shows planet HR8799b (5 times the mass of Jupiter), planets HR8799c and HR8799d (7 times the mass of Jupiter) and the new planet HR8799e. (The star itself is referred to as HR8799A.) Credit: NRC-HIA, Christian Marois, and the W.M. Keck Observator

Schematic representation of the HR8799 system compared to our own solar system, showing the 4 HR8799 planets and Jupiter, Saturn, Uranus and Neptune in our solar system. Infrared observations made by space telescopes have shown that the HR8799 system has massive, dusty asteroid belt, thousands of times more dense than our own, that is gravitationally shaped by HR8799e the same way Jupiter shapes our asteroid belt, and an outer belt of cometary debris similar to but much more massive than our own Kuiper belt.

Kamuela, HI, Dec. 8, 2010 - Astronomers have discovered a fourth giant planet joining three others that, in 2008, were the subject of the first-ever pictures of a planetary system orbiting another star other than our sun. In 2008, astronomers announced the first-ever pictures of a planetary family, showing three planets orbiting around a dusty young star named HR8799, which is 129 light years away. Credit: NRC-HIA, Christian Marois, and the W.M. Keck Observatory

Now, a research team from Lawrence Livermore National Laboratory (LLNL), National Research Council of Canada (NRC), the University of California Los Angeles, and Lowell Observatory has discovered a fourth planet that is about 7 times the mass of Jupiter – similar to the other three. Using high-contrast, near infrared adaptive optics on the Keck II telescope in Hawaii, the astronomers imaged the fourth planet (dubbed HR8799e) in 2009 and confirmed its existence and orbit in 2010. The research appears in the Dec. 8 edition of the journal, Nature.

“The images of this new inner planet in the system is the culmination of 10 years worth of innovations, making steady progress to optimize every observation and analysis step to allow the detection of planets located ever closer to their stars,” said Christian Marois, a former LLNL postdoc now at NRC, and first author of the new paper.

If this newly discovered planet was located in orbit around our sun, it would lie between Saturn and Uranus. This giant version of our solar system is young at about 30 million years old compared to our system, which is about 4.6 billion years old.

Though the system is very much like our own, in other ways, it is much more extreme than our own – the combined mass of the four giant planets may be 20 times higher, and the asteroid and comet belts are dense and turbulent. In fact, the massive planets’ pull on each other gravitationally, and the system may be on the verge of falling apart.

This team of scientists simulated millions of years of evolution of the system, and showed that to have survived this long, the three inner planets may have to orbit like clockwork, with the new planet going around the star exactly four times while the second planet finishes two orbits in the time it takes the outer planet to complete one. This behavior was first seen in the moons of Jupiter but has never before been seen on this scale.

Studying the planet’s orbits also will help estimate their masses. “Our simulations show that if the objects were not planets, but supermassive ‘brown dwarfs’, the system would have fallen apart already,” said Quinn Konopacky, a postdoctoral researcher at LLNL’s Institute of Geophysics and Planetary Physics and a key author of the paper. “The implication is that we have truly found a unique new system of planets.” (Brown dwarfs are “failed stars”, too low in mass to sustain stable hydrogen fusion but larger than planets.) “We don’t yet know if the system will last for billions of years, or fall apart in a few million more. As astronomers carefully follow the HR 8799 planets during the coming decades, the question of just how stable their orbits are could become much clearer.”

The origin of these four giant planets remains a puzzle. It neither follows the “core accretion” model, in which planets form gradually close to stars where the dust and gas are thick or the “disk fragmentation” model in which a turbulent planet-forming disk rapidly cools and collapses out at its edges. Bruce Macintosh, a senior scientist at LLNL and the principal investigator for the Keck Observatory program, said: “There’s no simple model that can make all four planets at their current location. It’s a challenge for our theoretical colleagues.”
Previous observations had shown evidence for a dusty asteroid belt orbiting closer to the star – the new planet’s gravity helps account for the location of those asteroids, confining their orbits just like Jupiter does in our solar system. “Besides having four giant planets, both systems contain also two so-called “debris belts” composed of small rocky and/or icy objects along with lots of tiny dust particles, similar to the asteroid and Kuiper comet belts of our solar system”, noted co-author Ben Zuckerman, a professor of physics and astronomy at UCLA.
“Images like these bring the exoplanet field into the era of characterization. Astronomers can now directly examine the atmospheric properties of four giant planets orbiting another star that are all the same young age and that formed from the same building materials.” said Travis Barman, a Lowell Observatory exoplanet theorist and co-author of the current paper.
“I think there’s a very high probability that there are more planets in the system that we can’t detect yet,” Macintosh said. “One of the things that distinguishes this system from most of the extrasolar planets that are already known is that HR8799 has its giant planets in the outer parts - like our solar system does - and so has ‘room’ for smaller terrestrial planets – far beyond our current ability to see – in the inner parts.”

“It’s amazing how far we’ve come in a few years,” Macintosh said. “In 2007, when we first saw the system, we could barely see two planets out past the equivalent of Pluto’s orbit. Now we’re imaging a fourth planet almost where Saturn is on our solar system. It’s another step to the ultimate goal – still more than a decade away – of a picture showing another planet like Earth.”

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea. The twin telescopes feature a suite of advanced instrumentation including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectroscopy and a world-leading laser guide star adaptive optics system. The Observatory is a private 501(c) 3 organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.