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New Submillimetre Camera Sheds Light on the Dark Regions of the Universe

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The stars and faint galaxies you see when you look up at the night sky are all emitting light within the visible light spectrum — the portion of the electromagnetic spectrum we can see with our unaided eyes or through optical telescopes. But our galaxy, and many others, contain huge amounts of cold dust that absorbs visible light. This accounts for the dark regions.

A new camera recently unveiled at the James Clerk Maxwell Telescope (JCMT) in Hawaii promises to figuratively shed light on this dark part of the universe. The SCUBA-2 submillimetre camera (SCUBA in this case is an acronym for Submillimetre Common-User Bolometer Array) can detect light at lower energy levels, allowing astronomers to gather data on these dark areas and ultimately learn more about our universe and its formation. 

Light is measurable; its intensity or brightness is measured by photons while colour is measured by the energy of the photons. Red photons have the least energy and violet photons have the most energy. This can also be thought of in terms of wavelengths. Light at longer wavelengths have less energy and light at shorter wavelengths have more energy. This continues beyond the visible light spectrum. As electromagnetic waves get shorter, we get ultraviolet light, x-rays, and gamma rays. As wavelengths get longer, we get infrared light, submillimetre light, and finally radio waves.

Panoramic view of the entire near-infrared sky reveals the distribution of galaxies beyond the Milky Way. Image credit: Thomas Jarrett, IPAC/Caltech.

On the longer end of the electromagnetic spectrum, infrared and radio telescopes have been around for decades helping astronomers understand more about the universe. But this is only part of the picture. The cold dust that absorbs the visible light to create the dark regions seen through optical telescopes is actually absorbing the light’s energy and reemitting it at longer wavelengths in the submillimetre region.

The first submillimetre camera, SCUBA, was designed and constructed at the Royal Observatory in Edinburgh in collaboration with the University of London. In 1997, it was up and running at the JCMT. Observations of submillimetre wavelengths are typically harder to gather — it takes a long time to image a small portion of the sky in this region. Nevertheless, submillimetre observations have already revealed a previously unknown population of distant, dusty galaxies as well as images of cold debris discs around nearby stars. This latter finding could be an indication of the presence of planetary systems.

A team of astronomers has recently developed the camera SCUBA-2 that can probe the submillimetre region with increased speed and much greater detail. But it’s a touchy instrument. Director of the JCMT Professor Gary Davis explains that for SCUBA-2 to detect extremely low energy radiation in the submillimetre region, “the instrument itself needs to be [extremely cold]. The detectors… have to be cooled to only 0.1 degree above absolute zero [–273.05°C], making the interior of SCUBA-2 colder than anything in the Universe that we know of!”

The infant Universe as imaged in the radio wavelength spectrum. Image Credit: NASA/WMAP Science Team.

The camera is a huge step in observational astronomy. Director of the United Kingdom Astronomy Teaching Centre Professor Ian Robson likened the technological leap between early sub-millimetre cameras and SCUBA-2 to the difference between wind-on film cameras and modern digital technology. “It is thanks to the ingenuity and abilities of our scientists and engineers that this immense leap in progress has been achieved,” he said.

Dr Antonio Chrysostomou, Associate Director of the JCMT, explains that SCUBA-2’s first task will be to carry out a series of surveys throughout the sky, mapping sites of star formation within our Galaxy, as well as planet formation around nearby stars. It will also survey our galactic neighbours and look into deep space to sample the youngest galaxies in the Universe. This latter task will be critical in helping astronomers understand how galaxies have evolved since the Big Bang.

The SCUBA-2 camera is housed on the 15 metre (about 50 foot) diameter JCMT situated close to the summit of Mauna Kea, Hawaii, at an altitude of 4092 metres (about 13,425 feet). It is typically used to study our Solar System, interstellar dust and gas, and distant galaxies.

Source: Revolutionary New Camera Reveals Dark Side of the Universe

 

The James Clerk Maxwell Telescope. Image credit: www.jach.hawaii.edu

 

 

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Mapping The Milky Way’s Magnetic Fields – The Faraday Sky

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Kudos to the scientists at the Max Planck Institut and an international team of radio astronomers for an incredibly detailed new map of our galaxy’s magnetic fields! This unique all-sky map has surpassed its predecessors and is giving us insight into the magnetic field structure of the Milky Way beyond anything so far seen. What’s so special about this one? It’s showing us a quality known as Faraday depth – a concept which works along a specific line of sight. To construct the map, data was melded from 41,000 measurements collected from a new image reconstruction technique. We can now see not only the major structure of galactic fields, but less obvious features like turbulence in galactic gas.

So, exactly what does a new map of this kind mean? All galaxies possess magnetic fields, but their source is a mystery. As of now, we can only guess they occur due to dynamo processes… where mechanical energy is transformed into magnetic energy. This type of creation is perfectly normal and happens here on Earth, the Sun, and even on a smaller scale like a hand-crank powered radio – or a Faraday flashlight! By showing us where magnetic field structures occur in the Milky Way, we can get a better understanding of galactic dynamos.

Fig. 1: The sky map of the Faraday effect caused by the magnetic fields of the Milky Way. Red and blue colors indicate regions of the sky where the magnetic field points toward and away from the observer, respectively. The band of the Milky Way (the plane of the galactic disk) extends horizontally in this panoramic view. The center of the Milky Way lies in the middle of the image. The North celestial pole is at the top left and the South Pole is at the bottom right.
For the last century and a half, we’ve known about Faraday rotation and scientists use it to measure cosmic magnetic fields. This action happens when polarized light goes through a magnetized medium and the plane of polarization revolves. The amount of turn is dependent on the strength and direction of the magnetic field. By observation of the rotation we can further understand the properties of the intervening magnetic fields. Radio astronomers gather and examine the polarized light from distant radio sources passing through our galaxy on its way to us. The Faraday effect can then be judged by measuring the source polarization at various frequencies. However, these measurements can only tell us about the one path through the Milky Way. To see things as a whole, one needs to know how many sources are scattered over the visible sky. This is where the international group of radio astronomers played an important role. They proved data from 26 different projects which gave a grand total of 41,300 pinpoint sources – at an average of about one radio source per square degree of sky.

Although that sounds like a wealth of information, it’s still not really enough. There are huge areas, particularly in the southern sky, where only a few measurements exist. Because of this lack of data, we have to interpolate between existing data points and that creates its own problems. First, the accuracy varies and more precise measurements should help. Also, astronomers are not exactly sure of how reliable a single measurement can be – they just have to take their best guess based on what information they have. Still, other problems exist. There are measurement uncertainties due to the complex nature of the process. A small error can increase by tenfold and this could convolute the map if not corrected. To help fix these problems, scientists at MPA developed a new algorithm for image capture, named the “extended critical filter”. In its creation, the team utilizes tools provided by the new discipline known as information field theory – a powerful tool that blends logical and statistical methods to applied fields and stacks it up against inaccurate information. This new work is exciting because it can also be applied to other imaging and signal-processing venues in alternate scientific fields.

Fig. 2: The uncertainty in the Faraday map. Note that the range of values is significantly smaller than in the Faraday map (Fig. 1). In the area of the celestial south pole, the measurement uncertainties are particularly high because of the low density of data points.
“In addition to the detailed Faraday depth map (Fig. 1), the algorithm provides a map of the uncertainties (Fig. 2). Especially in the galactic disk and in the less well-observed region around the south celestial pole (bottom right quadrant), the uncertainties are significantly larger.” says the team. “To better emphasize the structures in the galactic magnetic field, in Figure 3 (above) the effect of the galactic disk has been removed so that weaker features above and below the galactic disk are more visible. This reveals not only the conspicuous horizontal band of the gas disk of our Milky Way in the middle of the picture, but also that the magnetic field directions seem to be opposite above and below the disk. An analogous change of direction also takes place between the left and right sides of the image, from one side of the center of the Milky Way to the other.”

The good news is the galactic dynamo theory seems to be spot on. It has predicted symmetrical structures and the new map reflects it. In this projection, the magnetic fields are lined up parallel to the plane of the galactic disc in a spiral. This direction is opposite above and below the disc and the observed symmetries in the Faraday map arise from our location within the galactic disc. Here we see both large and small structures tied in with the turbulent, dynamic Milky Way gas structures. This new map algorithm has a great side-line, too… it characterizes the size distribution of these structures. Larger ones are more definitive than smaller ones, which is normal for turbulent systems. This spectrum can then be stacked against computer models of dynamics – allowing for intricate testing of the galactic dynamo models.

This incredible new map is more than just another pretty face in astronomy. By providing information of extragalactic magnetic fields, we’re enabling radio telescope projects such as LOFAR, eVLA, ASKAP, Meerkat and the SKA to rise to new heights. With this will come even more updates to the Faraday Sky and reveal the mystery of the origin of galactic magnetic fields.

Original Story Source: Max Planck Institut for Astrophysics News Release. For Further Reading: An improved map of the galactic Faraday sky”. Download the map HERE.

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SETI to Resume Search for Extraterrestrial Intelligence; Will Target Kepler Data

After being shut down for over six months due to financial problems, The Allen Telescope Array (ATA) is once again searching other planetary systems for radio signals, looking for evidence of extraterrestrial intelligence.

Some of the first targets in SETI’s renewed search will be a selection of recently discovered exoplanet candidates by NASA’s Kepler mission.

“This is a superb opportunity for SETI observations,” said Dr. Jill Tarter, the Director of the Center for SETI Research at the SETI Institute. “For the first time, we can point our telescopes at stars, and know that those stars actually host planetary systems – including at least one that begins to approximate an Earth analog in the habitable zone around its host star. That’s the type of world that might be home to a civilization capable of building radio transmitters.”

What other studies will SETI be performing with the array, and how were they able to restart the Allen Telescope Array?

This past April, SETI was forced to place the ATA into hibernation mode, due to budget cuts of SETI’s former partner, U.C Berkeley. Since Berkeley operated Hat Creek Observatory where the ATA is located, their withdrawal from the program left SETI without a way to operate the ATA.

SETI has since acquired new funding to operate the ATA and can now resume observations where they left off – examining planetary candidates detected by the Kepler mission. The planetary candidates SETI will examine first will be those that are thought to be in their star’s habitable zone (the range of orbital distance from a planet’s host star which may allow for surface water). Many astrobiologists theorize that liquid water is essential for life to exist on a planet.

“In SETI, as with all research, preconceived notions such as habitable zones could be barriers to discovery.” Tarter added. “So, with sufficient future funding from our donors, it’s our intention to examine all of the planetary systems found by Kepler.”

SETI will spend the next two years observing the planetary systems detected by Kepler in the naturally-quiet 1 to 10 GHz terrestrial microwave window. Part of what makes this comprehensive study possible is that the ATA can provide ready access to tens of millions of channels at any one time.

Resuming ATA operations was made possible due to tremendous public support via SETI’s www.SETIStars.org web site. In addition to the funds raised by the public, the United States Air Force has also provided funding to SETI in order to assess the ATA’s capabilities for space situational awareness.

Tarter notes, “Kepler’s success has created an amazing opportunity to focus SETI research. While discovery of new exoplanets via Kepler is backed with government monies, the search for evidence that some of these worlds might be home to intelligence falls to SETI alone. And our SETI exploration depends entirely on private donations, for which we are deeply grateful to our donors.”

“The year-in and year-out fundraising challenge we tackle in order to conduct SETI research is an absolute human and organizational struggle,” said Tom Pierson, CEO of the SETI Institute, “yet it is well worth the hard work to help Jill’s team address what is one of humanity’s most profound research questions.”

Dr. Tarter will be presenting during the first Kepler Science Conference (at NASA Ames Research Center) from December 5 to 9, 2011. You can view the agenda for the meeting, along with the abstract for her talk on Earth analogs at: http://kepler.nasa.gov/Science/ForScientists/keplerconference/sessions/.

If you’d like to learn more about SETI, or would like to make a donation to help fund their efforts, visit: https://setistars.org/donations/new

Read more about SETI’s partnership with the United States Air Force at: http://www.seti.org/afspc

Source: SETI Institute press release

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Astronomers Find the Justin Bieber of Millisecond Pulsars

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Astronomers using the Fermi Gamma-ray Space Telescope have found a surprisingly young, powerful and luminous millisecond pulsar. Over the past three years, Fermi has detected more than 100 gamma-ray pulsars and typically the ages of these objects are at least a billion year old. But this new object is just a youngster, born only about 25 million years ago.

“It is a bit like finding Justin Bieber when you thought you were at a Rolling Stones concert,” said Victoria Kaspi, physics professor, McGill University in Montreal, during a teleconference about two new discoveries made with the Fermi telescope. “Fermi has represented a huge leap forward in finding things that couldn’t have been imagined 25 years ago.”

In addition to the very young and bright pulsar, researchers announced they have also discovered a set of nine previously unknown gamma-ray pulsars, a new type that have extremely low luminosity. These were uncovered with a new technique to more efficiently sift through Fermi data.

The young millisecond pulsar, named PSR J1823?3021A was found within the globular cluster NGC 6624, not far from the center of our galaxy. Fermi has detected pulsars in globular clusters before, but usually what it finds are the combined gamma rays from many ancient pulsars within the clusters. But this time, surprisingly, the gamma rays originated from just one very powerful millisecond pulsar.

“At first we thought it was perhaps one hundred millisecond pulsars, but now we see it is just one,” said Paulo Freire, from the Max Planck Institute for Radio Astronomy in Bonn, Germany, also speaking to reporters during the teleconference. Freire is the lead author on a new paper published in the Astrophysical Journal. “It must have formed recently based on how rapidly it’s emitting energy. It’s a bit like finding a screaming baby in a quiet retirement home. This was a rather surprising discovery for everyone involved.”

A pulsar is a type of neutron star that emits electromagnetic energy at periodic intervals, sending out signals almost like a lighthouse. Pulsars that combine incredible density with extreme rotation are called millisecond pulsars. These millisecond pulsars are especially fascinating, as they are city-sized spheres about half millions times Earth’s mass, spinning at up to 43,000 revolutions per minute.

Millisecond pulsars are thought to achieve such speeds because they are gravitationally bound in binary systems with normal stars. During part of their stellar lives, gas flows from the normal star to the pulsar. Over time, the impact of this falling gas gradually spins up the pulsar’s rotation.

This plot shows the positions of nine new pulsars (magenta) discovered by Fermi and of an unusual millisecond pulsar (green) that Fermi data reveal to be the youngest such object known. With this new batch of discoveries, Fermi has detected more than 100 pulsars in gamma rays. Credit: AEI and NASA/DOE/Fermi LAT Collaboration

The nine new low luminosity pulsars found with Fermi emit less gamma radiation than those previously known and rotate only between three and twelve times per second. Only one of these pulsars was later also found to emit radio waves. Without the new technique, astronomers wouldn’t have found this faint pulsars.

““We used a new kind of hierarchical algorithm which we had originally developed for the search for gravitational waves, and we were quickly rewarded,” said Bruce Allen, director of the Max Planck Institute for Gravitational Physics, a co-author on the recent discoveries.

Using what is called a blind search, computers check many different combinations of position and rotational behavior, to see if they match the arrival times of photons hitting the Fermi Large Area Telescope (LAT) coming from the same direction. The search used the 8,000 photons deemed most probable to come from a pulsar at the recognized position, which Fermi’s LAT had collected during its three years in orbit. When the photon arrival times match up with the putative pulsar position and rotation model, a regular pattern of peaks appears in the gamma-ray photon counts, as a function of the rotational position of the pulsar, and a new gamma-ray pulsar has been discovered.

“It is a little like sifting through a pile of sand looking for diamonds,” Allen said, adding that the search is ongoing and they hope to find more.

Additionally, Allen said, users of the [email protected] project can now be part of this search, to help specifically to search for the first pure gamma-ray millisecond-pulsar. Allen is the director of this project and said this discovery would be a significant contribution to our understanding of pulsars.

NASA has a new interactive web feature about Fermi and the 100 pulsars it has now found.

Sources: Max Planck Institute, NASA, More info, images and vidoes at this NASA page

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NASA Prepares for Asteroid’s Close Pass by Earth

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On Tuesday, November 8, at 6:28 p.m. EST, an asteroid the size of an aircraft carrier will soar past our planet at a distance closer than the Moon… and NASA scientists will be watching!

2005 YU55, a 400-meter (1,300-foot) -wide C-type asteroid, was discovered in December 2005 by Robert McMillan of the Spacewatch Program at the University of Arizona, Tucson. It’s pretty much spherical in shape and dark – darker than charcoal, in fact! Scientists with NASA’s Near-Earth Objects Observation Program will begin tracking it on November 4 using the 70-meter radar telescope at the Deep Space Network in Goldstone, California , as well as with the Arecibo Planetary Radar Facility in Puerto Rico beginning November 8. They will continue tracking 2005 YU55 through November 10.

Animation of 2005 YU55's trajectory on Nov. 8. (NASA/JPL) Click to play.

YU55’s orbit is well understood by scientists. It has come this way before, and although this is the closest it’s come to Earth in at least two centuries it will still be at least 324,600 kilometers (201,700 miles) away at nearest approach. That’s about 85% of the distance to the Moon.

It will approach from the sunward side, making viewing in visible light difficult until after it’s made its closest pass.

Other than the excitement it will most likely cause amongst radar astronomers, 2005 YU55 will have no physical effect on our planet. (There have been some rumors circulating online about this particular asteroid’s upcoming pass, in regards to earthquakes and tidal fluctuations and atmospheric disturbances and other such nonsense… the bottom line is that, like the ill-fated comet Elenin, 2005 YU55 has never been known to pose any threat to Earth.)

“YU55 poses no threat of an Earth collision over, at the very least, the next 100 years,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office at JPL. “During its closest approach, its gravitational effect on the Earth will be so miniscule as to be immeasurable. It will not affect the tides or anything else.”

The 70m telescope at the Goldstone Deep Space Communications Complex in California's Mojave Desert. (NASA/JPL)

Scientists are very eager though to have a prime opportunity to study this quarter-mile-wide world as it makes its closest pass. The giant telescopes at Goldstone and Arecibo will bounce radar waves off the asteroid, mapping its size and shape, and hopefully obtain some very high-resolution images.

“Using the Goldstone radar operating with the software and hardware upgrades, the resulting images of YU55 could come in with resolution as fine as 4 meters per pixel. We’re talking about getting down to the kind of surface detail you dream of when you have a spacecraft fly by one of these targets.”

– Lance Benner, JPL radio astronomer

Even though YU55 will remain at a safe distance the event is still quite notable. The last time an object this large came so close to Earth was in 1976… and scientists weren’t even aware of it at the time. Luckily we now have programs like the Near-Earth Objects Observations Program – a.k.a. “Spaceguard” –  to identify asteroids like this, hopefully in time to know if they could become a danger to our planet in either the near or distant future.

As of now, no large space rock with Earth’s name on it has been positively identified… but that doesn’t mean there’s nothing out there either. We need to keep diligent, keep looking and, above all, keep funding programs like this. If anything, this pass should serve as a reminder – however harmless – that we certainly are not alone in the solar system!

Read more on the NASA/JPL press release here.

UPDATE: NASA will be holding a live Q&A on 2005 YU55 and other near-Earth objects on November 1 at 2:30 p.m. PDT (5:30 p.m. EDT)… watch live here.

 

 

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Black Hole Secrets… Water Vapor Gives Clues To Star Formation

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A eye-opening discovery has been made by an international team of scientists led by astronomer Paul van der Werf (Leiden University, The Netherlands). They have discovered a black hole in the early Universe located about 12 billion light years away that’s surrounded by a nearly impenetrable disk of gas and dust. The halo isn’t the surprise, however… but the presence of star formation in dense water vapor is.

Using the sensitive radio telescopes of IRAM (Institut de Radioastronomie Millimétrique) at the Plateau de Bure in the French Alps, the team was searching for the signs of water vapor around a quasar – a distant galaxy which gathers its luminosity from the growth of a black hole which weighs in at hundreds of millions times more mass than Sol.

“Water in cosmic clouds is normally frozen to ice, but the ice can be evaporated by the strong radiation of the quasar or of young stars. Therefore we decided to search for water vapor in this object.” says van der Werf. “It is located so far away that we are looking back in time, to an era where the Universe was only 10% of its present age. This is one of the first searches ever conducted to find water in the early Universe.”

A shocking revelation? Not really. Water vapor has been discovered before. In this instance, however, the water amounted to about 1,000 trillion times the volume found on Earth. What’s more… it’s forming stars. It’s a dense disk, so thick that light barely escapes, and star propagation is rapid.

“Water molecules are sensitive to infrared radiation, so we could use the water vapor detected as a cosmic infrared light meter. With this method we found that essentially all radiation is locked up in the gas disk surrounding the black hole.” team member Marco Spaans (University of Groningen, The Netherlands) explains. “This trapped radiation is so intense that it will build up enormous pressure and eventually blow away the gas and dust clouds surrounding the black hole.”

These findings add a new complexity to our understanding of black holes and the galaxies which hold them. Team member Alicia Berciano Alba (ASTRON, The Netherlands) says: “There is a mysterious relation between the masses of black holes in the centers of galaxies and the masses of the galaxies themselves, as if the formation of both is regulated by the same process. Our results show that these opaque gas disks, which will be ultimately blown away by the intense pressure of the trapped radiation, probably play a key role in this process.” IRAM director Pierre Cox, co-author of the paper, adds: “This discovery opens new possibilities for studying galaxies in the early Universe, using water molecules that probe regions closest to the central black hole, that are otherwise difficult to explore.”

Keep on going, because the IRAM team is up to the task and continuing to look for other sources of water vapor in the early Universe!

Original Story Source: Leiden University New Release. For Further Reading: Water vapor emission reveals a highly obscured, star forming nuclear region in the QSO host galaxy APM 08279+5255 at z=3.9.

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Help Give the Very Large Array a New Name

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The iconic Very Large Array is almost as much pop culture as science instrument. It’s been part of movie plots, on album covers, in comic books and video games. But now, the VLA is being transformed from its original 1970s-vintage technology with state-of-the-art equipment. The National Radio Astronomy Observatory says that the upgrades will increase the VLA’s technical capabilities by factors of as much as 8,000 and greatly increasing the array’s scientific impact.

And so to befit the VLA’s new capabilities, NRAO has decided the array should have a new name. And they are looking for some help from the public.

The Very Large Array CREDIT: NRAO/AUI/NSF

There is a special website, namethearray.org, where you can submit a name suggestion. You may enter a free-form name, or a word or phrase to come as a prefix before “Very Large Array,” or both.

Entries will be accepted until 23:59 EST on December 1, 2011, and the new name will be announced at NRAO’s Town Hall at the American Astronomical Society’s meeting in Austin, Texas, on Tuesday, January 10, 2012.

“The VLA Expansion Project, begun in 2000, has increased the VLA’s technical capabilities by factors of as much as 8,000, and the new system allows scientists to do things they never could do before,” said Fred K.Y. Lo, Director of the National Radio Astronomy Observatory. “After more than three decades on the frontiers of science, the VLA now is poised for a new era as one of the world’s premier tools for meeting the challenges of 21st-Century astrophysics.”

Source: NRAO

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Did The Draconids Perform?

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After weeks of speculation of its intensity, the Draconid/Giacobond meteor shower finally arrived. Some astronomers predicted that this normally quiet meteor shower would deliver up to 1000 meteors per hour at its peak – Were they right?

At approximately 20:00 BST (21:00 UT) on October 8th 2011 the shower started in earnest and many in the UK and Europe looked forward to an evening of meteor watching.

Unfortunately, many people were under thick clouds and missed the display, but there were a few places where the clouds cleared and observers were treated to a memorable spectacle.

I have done many meteorwatch evenings in the past, but this one got exciting very quickly and the uncertainty of the amount of meteors was soon doused.

Many people including myself were popping outside and trying to glimpse meteors through the clouds, but most of the time the Meteorwatch Meteor Live View was being used.

Everything was fairly sedate apart from us all moaning about the weather, but then all of a sudden at approximately 20:30 BST (19:30 UT) The Meteor Live View app on the Meteorwatch website went crazy!

Meteor Live View Credit: meteorwatch.org/ Norman Lockyer Observatory UK

Many people started to get good breaks in the clouds including myself and there were reports of dozens of meteors in just a few short minutes, much to the envy and disappointment of those still clouded over.

At this time the International Meteor Organisation (IMO) reported observations of just over 300 meteors per hour (319 ZHR).

The evening continued and to everybody’s delight (to those who could see meteors), there were many. I saw 3 within a couple of seconds and this continued for about an hour.

Eventually rates started to decline, people saw less and the Meteor Live View started to show less activity.

At approximately 22:00 BST (21:00 UT) meteor activity dropped substantially – The show was over!

The IMO results were posted on their website with rates of just under 350 meteors per hour at the peak of the shower, reported by their observing stations.

Credit: IMO

Did the Dracondids/ Giacobonids live up to expectations in the end? I would say yes, a fairly heavy meteor shower, maybe it could be called a mini storm!

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Even the Early Universe Had the Ingredients for Life

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For us carbon-based life forms, carbon is a fairly important part of the chemical makeup of the Universe. However, carbon and oxygen were not created in the Big Bang, but rather much later in stars. How much later? In a surprising find, scientists have detected carbon much earlier in the Universe’s history than previously thought.

Researchers from Ehime University and Kyoto University have reported the detection of carbon emission lines in the most distant radio galaxy known. The research team used the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope to observe the radio galaxy TN J0924-2201. When the research team investigated the detected carbon line, they determined that significant amounts of carbon existed less than a billion years after the Big Bang.

How does this finding contribute to our understanding of the chemical evolution of the universe and the possibilities for life?

To understand the chemical evolution of our universe, we can start with the Big Bang. According to the Big Bang theory, our universe sprang into existence about 13.7 billion years ago. For the most part, only Hydrogen and Helium ( and a sprinkle of Lithium) existed.

So how do we end up with everything past the first three elements on the periodic table?

Simply put, we can thank previous generations of stars. Two methods of nucleosythesis (element creation) in the universe are via nuclear fusion inside stellar cores, and the supernovae that marked the end of many stars in our universe.

Over time, through the birth and death of several generations of stars, our universe became less “metal-poor” (Note: many astronomers refer to anything past Hydrogen and Helium as metals”). As previous generations of stars died out, they “enriched” other areas of space, allowing future star-forming regions to have conditions necessary to form non-star objects such as planets, asteroids, and comets. It is believed that by understanding how the universe created heavier elements, researchers will have a better understanding of how the universe evolved, as well as the sources of our carbon-based chemistry.

So how do astronomers study the chemical evolution of our universe?

By measuring the metallicity (abundance of elements past Hydrogen on the periodic table) of astronomical objects at various redshifts, researchers can essentially peer back into the history of our universe. When studied, redshifted galaxies show wavelengths that have been stretched (and reddened, hence the term redshift) due to the expansion of our universe. Galaxies with a higher redshift value (known as “z”) are more distant in time and space and provide researchers information about the metallicity of the early universe. Many early galaxies are studied in the radio portion of the electromagnetic spectrum, as well as infra-red and visual.

The research team from Kyoto University set out to study the metallicity of a radio galaxy at higher redshift than previous studies. In their previous studies, their findings suggested that the main era of increased metallicity occurred at higher redshifts, thus indicating the universe was “enriched” much earlier than previous believed. Based on the previous findings, the team then decided to focus their studies on galaxy TN J0924-2201 – the most distant radio galaxy known with a redshift of z = 5.19.

The deep optical spectrum of TN J0924-2201 obtained with FOCAS on the Subaru Telescope. The red arrows point to the carbon emission line.

The research team used the FOCAS instrument on the Subaru Telescope to obtain an optical spectrum of galaxy TN J0924-2201. While studying TN J0924-2201, the team detected, for the first time, a carbon emission line (See above). Based on the detection of the carbon emission line, the team discovered that TN J0924-2201 had already experienced significant chemical evolution at z > 5, thus an abundance of metals was already present in the ancient universe as far back as 12.5 billion years ago.

If you’d like to read the team’s findings you can access the paper Chemical properties in the most distant radio galaxy – Matsuoka, et al at: http://arxiv.org/abs/1107.5116

Source: NAOJ Press Release

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First Look At Interstellar Turbulence

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All of the space that surrounds us isn’t empty. We’ve always known the Milky Way was filled with great areas of turbulent gas, but we’ve never been able to see them… Until now. Professor Bryan Gaensler of the University of Sydney, Australia, and his team used a CSIRO radio telescope in eastern Australia to create this first-ever look which was published in Nature today.

“This is the first time anyone has been able to make a picture of this interstellar turbulence,” said Professor Gaensler. “People have been trying to do this for 30 years.”

So what’s the point behind the motion? Turbulence distributes magnetism, disperses heat from supernova events and even plays a role in star formation.

“We now plan to study turbulence throughout the Milky Way. Ultimately this will help us understand why some parts of the galaxy are hotter than others, and why stars form at particular times in particular places,” Professor Gaensler said.

Employing CSIRO’s Australia Telescope Compact Array because “it is one of the world’s best telescopes for this kind of work,” as Dr. Robert Braun, Chief Scientist at CSIRO Astronomy and Space Science, explained, the team set their sights about 10,000 light years away in the constellation of Norma. Their goal was to document the radio signals which emanate from that section of the Milky Way. As the radio waves pass through the swirling gas, they become polarized. This changes the direction in which the light waves can “vibrate” and the sensitive equipment can pick up on these small differentiations.

By measuring the polarization changes, the team was able to paint a radio portrait of the gaseous regions where the turbulence causes the density and magnetic fields to fluctuate wildly. The tendrils in the image are also important, too. They show just how fast changes are occurring – critical for their description. Team member Blakesley Burkhart, a PhD student from the University of Wisconsin, made several computer simulations of turbulent gas moving at different speeds. By matching the simulations with the actual image, the team concluded “the speed of the swirling in the turbulent interstellar gas is around 70,000 kilometers per hour — relatively slow by cosmic standards.”

Original Story Source: CSIRO Astronomy and Space Science News Release. For Further Reading: Low Mach number turbulence in interstellar gas revealed by radio polarization gradients.