Image of NGC 6872 (left) and companion galaxy IC 4970 (right) locked in a tango as the two galaxies gravitationally interact. The galaxies lie about 200 million light-years away in the direction of the constellation Pavo (the Peacock). Image credit: Sydney Girls High School Astronomy Club, Travis Rector (University of Alaska, Anchorage), Ángel López-Sánchez (Australian Astronomical Observatory/Macquarie University), and the Australian Gemini Office.
Galaxy modelling is complicated, and even more so when different computer models don’t agree on how the factors come together. This makes it hard to understand the nature of our universe. One new project called AGORA (Assembling Galaxies of Resolved Anatomy) aims to resolve the discrepancies and make the results more consistent. Basically, the project aims to compare different codes against each other and also against observations.
“The physics of galaxy formation is extremely complicated, and the range of lengths, masses, and timescales that need to be simulated is immense,” stated Piero Madau, professor of astronomy and astrophysics at the University of California, Santa Cruz and co-chair of the AGORA steering committee.
“You incorporate gravity, solve the equations of hydrodynamics, and include prescriptions for gas cooling, star formation, and energy injection from supernovae into the code. After months of number crunching on a powerful supercomputer, you look at the results and wonder if that is what nature is really doing or if some of the outcomes are actually artifacts of the particular numerical implementation you used.”
This is especially important when it comes to modelling the effect of dark matter on the universe. Since the entity is hard for us to see and therefore to identify, physicists rely on models to make predictions about its effect on galaxies and other forms of more ordinary matter.
Nine codes, nine galaxy formation scenarios: this is the sort of problem that AGORA is devoting itself to resolving by comparing different supercomputer simulations. Credit: Simulations performed by Samuel Leitner (ART-II), Ji-hoon Kim (ENZO), Oliver Hahn (GADGET-2- CFS), Keita Todoroki (GADGET-3), Alexander Hobbs (GADGET-3-CFS and GADGET-3-AFS), Sijing Shen (GASOLINE), Michael Kuhlen (PKDGRAV-2), and Romain Teyssier (RAMSES)
“One big challenge, however, has been numerically modeling astrophysical processes over the vast range of size scales in the Universe. Supercomputer simulations are designed with three different size scales relevant to three different phenomena: star formation, galaxy formation, and the large scale structure of the universe,” stated the University of California High-Performance Astrocomputing Center.
This means that models of stars coming to be inside of galaxies have one scale of resolution — enough to look at what the gas and dust is made of, for example — but when looking at the entire universe, the computer is more limited to looking at “simple gravitational interactions of dark matter”, the university added. Of course, the more resolution you can get in a computer model, the better — especially because star formation is affected by processes such as how galaxies interact with surrounding gas.
AGORA’s will first aim to “model a realistic isolated disk galaxy” UCSC states, and then compare the codes used to see what they come up with. You can read more about the project’s aims at this Arxiv pre-print paper (led by the University of California, Santa Cruz’s Ji-hoon Kim) or on the AGORA website.
The Hubble Space Telescope image of the inner regions of the lensing cluster Abell 1689 that is 2.2 billion light?years away. Light from distant background galaxies is bent by the concentrated dark matter in the cluster (shown in the blue overlay) to produce the plethora of arcs and arclets that were in turn used to constrain dark energy. Image courtesy of NASA?ESA, Jullo (JPL), Natarajan (Yale), Kneib (LAM)
We keep saying dark matter is so very hard to find. Astronomers say they can see its effects — such as gravitational lensing, or an amazing bendy feat of light that takes place when a massive galaxy brings forward light from other galaxies behind it. But defining what the heck that matter is, is proving elusive. And considering it makes up most of the universe’s matter, it would be great to know what dark matter looks like.
A new experiment — billed as the most sensitive dark matter detector in the world — spent three months searching for evidence of weakly interacting massive particles (WIMPs), which may be the basis of dark matter. So far, nothing, but researchers emphasized they have only just started work.
“Now that we understand the instrument and its backgrounds, we will continue to take data, testing for more and more elusive candidates for dark matter,” stated physicist Dan McKinsey of Yale University, who is one of the collaborators on the Large Underground Xenon (LUX) detector.
A view of the Large Underground Xenon (LUX) dark matter detector. Shown are photomultiplier tubes that can ferret out single photons of light. Signals from these photons told physicists that they had not yet found Weakly Interacting Massive Particles (WIMPs) Credit: Matthew Kapust / South Dakota Science and Technology Authority
LUX operates a mile (1.6 kilometers) beneath the Earth in the state-owned Sanford Underground Research Facility, which is located in South Dakota. The underground location is perfect for this kind of work because there is little interference from cosmic ray particles.
“At the heart of the experiment is a six-foot-tall titanium tank filled with almost a third of a ton of liquid xenon, cooled to minus 150 degrees Fahrenheit. If a WIMP strikes a xenon atom it recoils from other xenon atoms and emits photons (light) and electrons. The electrons are drawn upward by an electrical field and interact with a thin layer of xenon gas at the top of the tank, releasing more photons,” stated the Lawrence Berkeley National Laboratory, which leads operations at Sanford.
“Light detectors in the top and bottom of the tank are each capable of detecting a single photon, so the locations of the two photon signals – one at the collision point, the other at the top of the tank – can be pinpointed to within a few millimeters. The energy of the interaction can be precisely measured from the brightness of the signals.”
The densest regions of the dark matter cosmic web host massive clusters of galaxies. Credit: Van Waerbeke, Heymans, and CFHTLens collaboration.
LUX’s sensitivity for low-mass WIMPs is more than 20 times better than other detectors. That said, the detector was unable to confirm possible hints of WIMPs found in other experiments.
“Three candidate low-mass WIMP events recently reported in ultra-cold silicon detectors would have produced more than 1,600 events in LUX’s much larger detector, or one every 80 minutes in the recent run,” the laboratory added.
Don’t touch that dial yet, however. LUX plans to do more searching in the next two years. Also, the Sanford Lab is proposing an even more sensitive LUX-ZEPLIN experiment that would be 1,000 times more sensitive than LUX. No word yet on when LUX-ZEPLIN will get off the ground, however.
Full sky map of the cosmic microwave background. The color red indicates a cool spot while the color blue indicates a hot spot. Image credit: NASA.
Warped visions of the cosmic microwave background – the earliest detectable light – allow astronomers to map the total amount of visible and invisible matter throughout the universe.
Roughly 85 percent of all matter in the universe is dark matter, invisible to even the most powerful telescopes, but detectable by its gravitational pull.
In order to find dark matter, astronomers look for an effect called gravitational lensing: when the gravitational pull of dark matter bends and amplifies light from a more distant object. In its most eccentric form it results in multiple arc-shaped images of distant cosmic objects.
The Hubble Space Telescope shows the effect of gravitational lensing as background galaxies are warped by the galaxy cluster MACS J1206. Image Credit: NASA
But there’s one caveat here: in order to detect dark matter there must be an object directly behind it. The ‘stars’ have to be aligned.
In a recent study led by Dr. James Geach of the University of Hertfordshire in the United Kingdom, astronomers have set their eyes on the cosmic microwave background (CMB) instead.
“The CMB is the most distant/oldest light we can see,” Dr. Geach told Universe Today. “It can be thought of as a surface, backlighting the entire universe.”
The photons from the CMB have been hurling toward the Earth since the universe was only 380,000 years old. A single photon has had the chance to run into plenty of matter, having effectively probed all the matter in the universe along its line of sight.
“So our view of the CMB is a bit distorted from what it intrinsically looks like – a bit like looking at the pattern on the bottom of a swimming pool,” Dr. Geach said.
By noting the small distortions in the CMB, we can probe all of the dark matter throughout the entire universe. But doing just this is extremely challenging.
The team observed the southern sky with the South Pole Telescope, a 10 meter telescope designed for observations in the microwave. This large, groundbreaking survey produced a CMB map of the southern sky, which was consistent with previous CMB data from the Planck satellite.
The characteristic signatures of gravitational lensing by intervening matter can not be extracted by eye. Astronomers relied on the use of a well-developed mathematical procedure. We wont go into the nasty details.
This produced a “map of the total projected mass density between us and the CMB. That’s quite incredible if you think about it – it’s an observational technique to map all of the mass in the universe, right back to the CMB,” Dr. Geach explained.
But the team didn’t finish their analysis there. Instead, they continued to measure the CMB lensing at the positions of quasars – powerful supermassive black holes in the centers of the earliest galaxies.
“We found that regions of the sky with a large density of quasars have a clearly stronger CMB lensing signal, implying that quasars are indeed located in large-scale matter structures,” Dr. Ryan Hickox of Dartmouth College – second author on the study – told Universe Today.
Finally, the CMB map was used to determine the mass of these dark matter halos. These results matched those determined in older studies, which looked at how the quasars clustered together in space, with no reference to the CMB at all.
Consistent results between two independent measurements is a powerful scientific tool. According to Dr. Hickox, it shows that “we have a strong understanding of how supermassive black holes reside in large-scale structures, and that (once again) Einstein was right.”
The paper has been accepted for publication in the Astrophysical Journal Letters and is available for download here.
Image from Dark Universe, showing the distribution of dark matter in the universe. Credit: AMNH
Atoms, string theory, dark matter, dark energy… there’s an awful lot about the Universe that might make sense on paper (to physicists, anyway) but is extremely difficult to detect and measure, at least with the technology available today. But at the core of science is observation, and what’s been observed of the Universe so far strongly indicates an overwhelming amount of… stuff… that cannot be observed. But just because it can’t be seen doesn’t mean it’s not there; on the contrary, it’s what we can’t see that actually makes up the majority of the Universe.
If this doesn’t make sense, that’s okay — they’re all pretty complex concepts. So in order to help non-scientists (which, like dark energy, most of the population is comprised of) get a better grasp as to what all this “dark” stuff is about, CERN scientist and spokesperson James Gillies has teamed up with TED-Ed animators to visually explain some of the Universe’s darkest secrets. Check it out above (and see more space science lessons from TED-Ed here.)
Because everything’s easier to understand with animation!
The Subaru Telescope. Credit: National Astronomical Observatory of Japan
Put another checkmark beside the “cold dark matter” theory. New observations by Japan’s Subaru Telescope are helping astronomers get a grip on the density of dark matter, this mysterious substance that pervades the universe.
We can’t see dark matter, which makes up an estimated 85 percent of the universe, but scientists can certainly measure its gravitational effects on galaxies, stars and other celestial residents. Particle physicists also are on the hunt for a “dark matter” particle — with some interesting results released a few weeks ago.
The latest experiment with Subaru measured 50 clusters of galaxies and found that the density of dark matter is largest in the center of these clusters, and smallest on the outskirts. These measurements are a close match to what is predicted by cold dark matter theory, scientists said.
Cold dark matter assumes that this material can’t be observed in any part of the electromagnetic spectrum, the band of light waves that ranges from high-energy X-rays to low-energy infrared heat. Also, the theory dictates that dark matter is made up of slow-moving particles that, because they collide with each other infrequently, are cold. So, the only way dark matter interacts with other particles is by gravity, scientists have said.
To check this out, Subaru peered at “gravitational lensing” in the sky — areas where the light of background objects are bent around dense, massive objects in front. Galaxy clusters are a prime example of these super-dense areas.
Several dark matter maps: one based on a sample of 50 individual galaxy clusters (left), another looking at an average galaxy cluster (center), and another based on dark matter theory (right). Red is the highest concentration of dark matter, followed by yellow, green and blue. At right, in the middle, is a map based on cold dark matter theory that comes close to the average galaxy cluster observed with the Suburu Telescope. Credit: NAOJ/ASIAA/School of Physics and Astronomy, University of Birmingham/Kavli IPMU/Astronomical Institute, Tohoku University)
“The Subaru Telescope is a fantastic instrument for gravitational lensing measurements. It allows us to measure very precisely how the dark matter in galaxy clusters distorts light from distant galaxies and gauge tiny changes in the appearance of a huge number of faint galaxies,” stated Nobuhiro Okabe, an astronomer at Academia Sinica in Taiwan who led the study.
Next, the team members could compare where the matter was most dense with that predicted by cold dark matter theory. To do that, they measured 50 of the most massive, known clusters of galaxies. Then, they measured the “concentration parameter”, or the cluster’s average density.
“They found that the density of dark matter increases from the edges to the center of the cluster, and that the concentration parameter of galaxy clusters in the near universe aligns with CDM theory,” stated the National Astronomical Observatory of Japan.
The next step, researchers stated, is to measure dark matter density in the center of the galaxy clusters. This could reveal more about how this substance behaves. Check out more about this study in Astrophysical Journal Letters.
Map showing all galaxies in the local universe color-coded by their distance to us: blue galaxies are the closest, and red are farther, up to 300 million light-years away. Credit: University of Hawaii.
Researchers with the Cosmic Flows project have been working to map both visible and dark matter densities around our Milky Way galaxy up to a distance of 300 million light-years, and they’ve now released this new video map which shows the motions of structures of the nearby Universe in greater detail than ever before.
“The complexity of what we are seeing is almost overwhelming,” says researcher Hélène Courtois, associate professor at the University of Lyon, France, and associate researcher at the Institute for Astronomy (IfA), University of Hawaii (UH) at Manoa. Courtois narrates the video.
The video zooms into our local area of the Universe — our Milky Way galaxy lies in a supercluster of 100,000 galaxies — and then slowly draws back to show the cosmography of the Universe out to 300 million light years.
The map shows how the large-scale structure of the Universe is a complex web of clusters, filaments, and voids. Large voids are bounded by filaments that form superclusters of galaxies. These are the largest structures in the universe.
The team explains:
The movements of the galaxies reveal information about the main constituents of the Universe: dark energy and dark matter. Dark matter is unseen matter whose presence can be deduced only by its effect on the motions of galaxies and stars because it does not give off or reflect light. Dark energy is the mysterious force that is causing the expansion of the universe to accelerate.
Night time blast off of 4 stage NASA Black Brant XII suborbital rocket at 11:05 p.m. EDT on June 5, 2013 from the NASA Wallops Flight Facility carrying the CIBER astronomy payload to study when the first stars and galaxies formed in the universe. The Black Brant soars above huge water tower at adjacent Antares rocket launch pad at NASA Wallops. Credit: Ken Kremer- kenkremer.com
Night time blast off of 4 stage NASA Black Brant XII suborbital rocket at 11:05 p.m. EDT on June 5, 2013 from the NASA Wallops Flight Facility carrying the CIBER astronomy payload to study when the first stars and galaxies formed in the universe. The Black Brant soars above huge water tower at adjacent Antares rocket launch pad at NASA Wallops. Credit: Ken Kremer- kenkremer.com Updated with more photos[/caption]
WALLOPS ISLAND, VA – The spectacular night time launch of a powerful Black Brant XII suborbital rocket from NASA’s launch range at the Wallops Flight Facility on Virginia’s Eastern Shore at 11:05 p.m. June 5 turned darkness into day as the rocket swiftly streaked skyward with the Cosmic Infrared Background ExpeRiment (CIBER) on a NASA mission to shine a bright beacon for science on star and galaxy formation in the early Universe.
A very loud explosive boom shook the local launch area at ignition that was also heard by local residents and tourists at distances over 10 miles away, gleeful spectators told me.
“The data looks good so far,” Jamie Bock, CIBER principal investigator from the California Institute of Technology, told Universe Today in an exclusive post-launch interview inside Mission Control at NASA Wallops. “I’m very happy.”
Ignition of NASA Black Brant XII suborbital rocket following night time launch at 11:05 p.m. EDT on June 5, 2013 from the NASA Wallops Flight Facility at the eastern Virginia shoreline. The launch pad sits in front of the Antares rocket Launch Complex 0A dominated by the huge water tower. The rocket carried the CIBER astronomy payload to an altitude of approximately 358 miles above the Atlantic Ocean to study when the first stars and galaxies formed in the universe and how brightly they burned their nuclear fuel. Credit: Ken Kremer- kenkremer.com
The four stage Black Brant XII is the most powerful sounding rocket in America’s arsenal for scientific research.
“I’m absolutely thrilled with this launch and this is very important for Wallops,” William Wrobel, Director of NASA Wallops Flight Facility, told me in an exclusive interview moments after liftoff.
Wallops is rapidly ramping up launch activities this year with two types of powerful new medium class rockets – Antares and Minotaur V- that can loft heavy payloads to the International Space Station (ISS) and to interplanetary space from the newly built pad 0A and the upgraded, adjacent launch pad 0B.
“We have launched over 16,000 sounding rockets.”
“Soon we will be launching our first spacecraft to the moon, NASA’s LADEE orbiter. And we just launched the Antares test flight on April 21.”
I was delighted to witness the magnificent launch from less than half a mile away with a big group of cheering Wallops employees and Wallops Center Director Wrobel. See my launch photos and time lapse shot herein.
Everyone could hear piercing explosions as each stage of the Black Brant rocket ignited as it soared to the heavens to an altitude of some 358 miles above the Atlantic Ocean.
Seconds after liftoff we could see what looked like a rain of sparkling fireworks showing downward towards the launch pad. It was a fabulous shower of aluminum slag and spent ammonium perchlorate rocket fuel.
A powerful NASA Black Brant XII suborbital rocket streaks spectacularly into the night sky following its launch at 11:05 p.m. EDT on June 5, 2013 from the NASA Wallops Flight Facility at the eastern Virginia shoreline. The launch pad sits in front of the Antares rocket Launch Complex 0A dominated by the huge water tower. The rocket carried the Cosmic Infrared Background ExpeRiment (CIBER) to an altitude of approximately 358 miles above the Atlantic Ocean to study when the first stars and galaxies formed in the universe and how brightly they burned their nuclear fuel. Side firing thrusters have ignited to impart stabilizing spin as rocket ascends above launch rail. Credit: Ken Kremer- kenkremer.com
The awesome launch took place on a perfectly clear night drenched with brightly shining stars as the Atlantic Ocean waves relentlessly pounded the shore just a few hundred feet away.
The rocket zoomed past the prominent constellation Scorpius above the Atlantic Ocean.
In fact we were so close that we could hear the spent first stage as it was plummeting from the sky and smashed into the ocean, perhaps 10 miles away.
After completing its spectral collection to determine when did the first stars and galaxies form and how brightly did they shine burning their nuclear fuel, the CIBER payload splashed down in the Atlantic Ocean and was not recovered.
Time lapse view of night launch of NASA Black Brant XII suborbital rocket zooming past constellation Scorpius (left) at 11:05 p.m. EDT above Atlantic Ocean on June 5, 2013 from the NASA Wallops Flight Facility carrying the CIBER astronomy payload. Credit: Ken Kremer- kenkremer.comNight time launch of NASA Black Brant XII suborbital rocket at 11:05 p.m. EDT on June 5, 2013 from the NASA Wallops Flight Facility carrying the CIBER astronomy payload. Credit: Ken Kremer- kenkremer.com
NASA said the launch was seen from as far away as central New Jersey, southwestern Pennsylvania and northeastern North Carolina.
One of my astronomy friends Joe Stieber, did see the launch from about 135 miles away in central New Jersey and captured beautiful time lapse shots (see below).
Time lapse view of June 5 launch of Blank Brant XII sounding rocket from Wallops Island as seen from Carranza Field in Wharton State Forest, NJ (about 135 miles north from Wallops). Scorpius is above the trees at the far left. Credit: Joe Stieber- sjastro.com
Everything with the rocket and payload went exactly as planned.
“This was our fourth and last flight of the CIBER payload,” Bock told me. “We are still analyzing data from the last 2 flights.”
“CIBER first flew in 2009 atop smaller sounding rockets launched from White Sands Missile Range, N.M. and was recovered.”
“On this flight we wanted to send the experiment higher than ever before to collect more measurements for a longer period of time to help determine the brightness of the early Universe.”
CIBER is instrumented with 2 cameras and 2 spectrometers.
“The payload had to be cooled to 84 Kelvin with liquid nitrogen before launch in order for us to make the measurements,” Bock told me.
“The launch was delayed a day from June 4 because of difficulty both in cooling the payload to the required temperature and in keeping the temperature fluctuations to less than 100 microkelvins,” Bock explained
The CIBER experiment involves scientists and funding from the US and NASA, Japan and South Korea.
Bock is already thinking about the next logical steps with a space based science satellite.
Space.com has now featured an album of my CIBER launch photos – here
Night launch of NASA Black Brant XII suborbital rocket at 11:05 p.m. EDT on June 5, 2013 from NASA Wallops Flight Facility, VA carrying CIBER astronomy payload. Credit: Ken Kremer
And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013
June 23: “Send your Name to Mars on MAVEN” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
Aerial view of NASA Wallops launch site on Virginia shore shows launch pads for both suborbital and orbital rockets. CIBER’s Black Brant XII rocket blasted off just behind the Pad 0A water tower. This photo was snapped from on top of Pad 0B that will soon launch NASA‘s LADEE orbiter to the Moon. Credit: Ken Kremer- kenkremer.comNASA’s CIBER experiment seeks clues to the formation of the first stars and galaxies. CIBER blasted off on June 5 from the NASA Wallops Flight Facility, Virginia. It will study the total sky brightness, to probe the component from first stars and galaxies using spectral signatures, and searches for the distinctive spatial pattern seen in this image, produced by large-scale structures from dark matter. This shows a numerical simulation of the density of matter when the universe was one billion years old. Galaxies formation follows the gravitational wells produced by dark matter, where hydrogen gas coalesces, and the first stars ignite. Credit: Volker Springel/Virgo Consortium.NASA Time lapse view shows multiple stages firing during night launch of NASA Black Brant XII suborbital rocket at 11:05 p.m. EDT above Atlantic Ocean on June 5, 2013 from the NASA Wallops Flight Facility carrying the CIBER astronomy payload. Credit: NASA/Jamie AdkinsNASA Black Brant XII suborbital rocket streaks skyward after blastoff at 11:05 p.m. EDT on June 5, 2013 from NASA Wallops Flight Facility, VA carrying CIBER astronomy payload. Credit: Ken Kremer
NASA’s CIBER experiment seeks clues to the formation of the first stars and galaxies. It will study the total sky brightness, to probe the component from first stars and galaxies using spectral signatures, and searches for the distinctive spatial pattern seen in this image, produced by large-scale structures from dark matter. This shows a numerical simulation of the density of matter when the universe was one billion years old. Galaxies formation follows the gravitational wells produced by dark matter, where hydrogen gas coalesces, and the first stars ignite. Credit: Volker Springel/Virgo Consortium.
When did the first stars and galaxies form in the universe and how brightly did they burn?
Scientists are looking for tell-tale signs of galaxy formation with an experimental payload called CIBER.
NASA will briefly turn night into day near midnight along the mid-Atlantic coastline on June 4 – seeking answers to illuminate researchers theories about the beginnings of our Universe with the launch of the Cosmic Infrared Background ExpeRiment (CIBER) from NASA’s launch range at the Wallops Flight Facility along Virginia’s eastern shoreline. See viewing map below.
CIBER will blast off atop a powerful four stage Black Brant XII suborbital rocket at 11 PM EDT Tuesday night, June 4. The launch window extends until 11:59 PM EDT.
Currently the weather forecast is excellent.
The public is invited to observe the launch from an excellent viewing site at the NASA Visitor Center at Wallops which will open at 9:30 PM on launch day.
The night launch will be visible to spectators along a long swath of the US East coast from New Jersey to North Carolina; if the skies are clear as CIBER ascends to space to an altitude of over 350 miles and arcs over on a southeasterly trajectory.
Backup launch days are available from June 5 through 10.
Launch visibility map for the CIBER payload launch from NASA Wallops, Va, on June 4, 2013 at 11 PM EDT. Credit: NASA
“The objectives of the experiment are of fundamental importance for astrophysics: to probe the process of first galaxy formation. The measurement is extremely difficult technically,” said Jamie Bock, CIBER principal investigator from the California Institute of Technology
Over the past several decades more than 20,000 sounding rockets have blasted off from an array of launch pads at Wallops, which is NASA’s lead center for suborbital science.
The Black Brant XII sounding rocket is over 70 feet tall.
The launch pad sits adjacent to the newly constructed Pad 0A of the Virginia Spaceflight Authority from which the Orbital Sciences Antares rocket blasted off on its maiden flight on April 21, 2013.
“The first massive stars to form in the universe produced copious ultraviolet light that ionized gas from neutral hydrogen. CIBER observes in the near infrared, as the expansion of the universe stretched the original short ultraviolet wavelengths to long near-infrared wavelengths today.”
“CIBER investigates two telltale signatures of first star formation — the total brightness of the sky after subtracting all foregrounds, and a distinctive pattern of spatial variations,” according to Bock.
Preparing the CIBER instrument for flight. The optics and detectors are cooled by liquid nitrogen to -19C (77 K, -312F) during the flight to eliminate infrared emission from the instrument and to achieve the best detector sensitivity. Photo: NASA/Berit Bland
This will be the fourth launch of CIBER since 2009 but the first from Wallops. The three prior launches were all from the White Sands Missile Range, N.M. and in each case the payload was recovered and refurbished for reflight.
However the June 4 launch will also be the last hurrah for CIBER.
The scientists are using a more powerful Black Brant rocket to loft the payload far higher than ever before so that it can make measurements for more than twice as long as ever before.
The consequence of flying higher is that CIBER will splashdown in the Atlantic Ocean, about 400 miles off the Virgina shore and will not be recovered.
You can watch the launch live on NASA Ustream beginning at 10 p.m. on launch day at: http://www.ustream.com/channel/nasa-wallops
I will be onsite at Wallops for Universe Today.
And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013
…………….
Learn more about Conjunctions, Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations
June 4: “Send your Name to Mars on MAVEN” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8:30 PM
NASA’s CIBER payload will launch from a suborbital launch pad located directly behind this Antares rocket erected at Pad 0A at the NASA Wallops Flight Facility along the Eastern shore of Virginia. Only a few hundred feet of beach sand and a miniscule sea wall separate the Wallops Island pads from the Atlantic Ocean waves and Mother Nature.
Credit: Ken Kremer (kenkremer.com)
This combined graphic shows new, high-resolution GBT imaging (in box) of recently discovered hydrogen clouds between M31 (upper right) and M33 (bottom left). Credit: Bill Saxton, NRAO/AUI/NSF.
Score another point for the National Science Foundation’s Green Bank Telescope (GBT) at the National Radio Astronomy Observatory (NRAO) in Green Bank. They have opened our eyes – and ears – to previously undetected region of hydrogen gas clouds located in the area between the massive Andromeda and Triangulum galaxies. If researchers are correct, these dwarf galaxy-sized sectors of isolated gases may have originated from a huge store of heated, ionized gas… Gas which may be associated with elusive and invisible dark matter.
“We have known for some time that many seemingly empty stretches of the Universe contain vast but diffuse patches of hot, ionized hydrogen,” said Spencer Wolfe of West Virginia University in Morgantown. “Earlier observations of the area between M31 and M33 suggested the presence of colder, neutral hydrogen, but we couldn’t see any details to determine if it had a definitive structure or represented a new type of cosmic feature. Now, with high-resolution images from the GBT, we were able to detect discrete concentrations of neutral hydrogen emerging out of what was thought to be a mainly featureless field of gas.”
So how did astronomers detect the extremely faint signal which clued them to the presence of the gas pockets? Fortunately, our terrestrial radio telescopes are able to decipher the representative radio wavelength signals emitted by neutral atomic hydrogen. Even though it is commonplace in the Universe, it is still frail and not easy to observe. Researchers knew more than 10 years ago that these repositories of hydrogen might possibly exist in the empty space between M33 and M32, but the evidence was so slim that they couldn’t draw certain conclusions. They couldn’t “see” fine grained structure, nor could they positively identify where it came from and exactly what these accumulations meant. At best, their guess was it came from an interaction between the two galaxies and that gravitational pull formed a weak “bridge” between the two large galaxies.
The animation demonstrates the difference in resolution from the original Westerbork Radio Telescope data (Braun & Thilker, 2004) and the finer resolution imaging of GBT, which revealed the hydrogen clouds between M31 and M33. Bill Saxton, NRAO/AUI/NSF Credit: Bill Saxton, NRAO/AUI/NSF.
Just last year, the GBT observed the tell-tale fingerprint of hydrogen gas. It might be thin, but it is plentiful and it’s spread out between the galaxies. However, the observations didn’t stop there. More information was gathered and revealed the gas wasn’t just ethereal ribbons – but solid clumps. More than half of the gas was so conspicuously aggregated that they could even have passed themselves off as dwarf galaxies had they a population of stars. What’s more, the GBT also studied the proper motion of these gas pockets and found they were moving through space at roughly the same speed as the Andromeda and Triangulum galaxies.
“These observations suggest that they are independent entities and not the far-flung suburbs of either galaxy,” said Felix J. Lockman, an astronomer at the NRAO in Green Bank. “Their clustered orientation is equally compelling and may be the result of a filament of dark matter. The speculation is that a dark-matter filament, if it exists, could provide the gravitational scaffolding upon which clouds could condense from a surrounding field of hot gas.”
And where there is neutral hydrogen gas, there is fuel for new stars. Astronomers also recognize these new formations could eventually be drawn into M31 and M33, eliciting stellar creation. To add even more interest, these cold, dark regions which exist between galaxies contain a large amount of “unaccounted-for normal matter” – perhaps a clue to dark matter riddle and the reason behind the amount of hydrogen yet to revealed in universal structure.
“The region we have studied is only a fraction of the area around M31 reported to have diffuse hydrogen gas,” said D.J. Pisano of West Virginia University. “The clouds observed here may be just the tip of a larger population out there waiting to be discovered.”
The international Super Cryogenic Dark Matter Search (SuperCDMS) has detected what may be the particle that's thought to make up dark matter throughout the Universe.
Dark matter: it’s invisible, it’s elusive, it’s controversial… and it’s everywhere — in the Universe, yes, but especially in the world of astrophysics, where researchers have been exhaustively trying to reveal its true identity for decades.
Now, scientists with the international Super Cryogenic Dark Matter Search (SuperCDMS) experiment are reporting the detection of a particle that’s thought to make up dark matter: a weakly-interacting massive particle, or WIMP. According to a press release from Texas A&M University (whose high-energy physicist Rupak Mahapatra is a principal investigator in the experiment) SuperCDMS has identified a WIMP-like signal at the 3-sigma level, which indicates a 99.8 percent chance of an actual discovery — a “concrete hint,” as it’s being called.
“In high-energy physics, a discovery is only claimed at 5-sigma or better,” Mahapatra said. “So this is certainly very exciting, but not fully convincing by the standards. We just need more data to be sure. For now, we have to live with this tantalizing hint of one of the biggest puzzles of our time.”
If this is indeed a WIMP it will be the first time such a particle has been directly observed, lending more insight into what dark matter is… or isn’t.
Notoriously elusive, WIMPs rarely interact with normal matter and therefore are difficult to detect. Scientists believe they occasionally bounce off, or scatter like billiard balls from, atomic nuclei, leaving behind a small amount of energy capable of being tracked by detectors deep underground, particle colliders such as the Large Hadron Collider at CERN and even instruments in space like the Alpha Magnetic Spectrometer (AMS) mounted on the International Space Station.
A stack of crystal germanium CDMS detectors (Fermilab)
The CDMS experiment, located a half-mile underground at the Soudan mine in northern Minnesota and managed by the United States Department of Energy’s Fermi National Accelerator Laboratory, has been searching for dark matter since 2003. The experiment uses very sophisticated detector technology and advanced analysis techniques to enable cryogenically cooled (almost absolute zero temperature at -460 degrees F) germanium and silicon targets to search for the rare recoil of dark matter particles.
This newly-announced detection actually comes from data acquired during an earlier phase of the experiment.
“This result is from data taken a few years ago using silicon detectors manufactured at Stanford that are now defunct,” Mahapatra said. “Increased interest in the low mass WIMP region motivated us to complete the analysis of the silicon-detector exposure, which is less sensitive than germanium for WIMP masses above 15 giga-electronvolts [one GeVa is equal to a billion electron volts] but more sensitive for lower masses. The analysis resulted in three events, and the estimated background is 0.7 events.”
Although Mahapatra says the result is certainly encouraging and worthy of further investigation, he cautions it should not be considered a discovery just yet.
“We are only 99.8 percent sure, and we want to be 99.9999 percent sure,” Mahapatra said. “At 3-sigma, you have a hint of something. At 4-sigma, you have evidence. At 5-sigma, you have a discovery.”
“In medicine, you can say you are curing 99.8 percent of the cases, and that’s OK. When you say you’ve made a fundamental discovery in high-energy physics, you can’t be wrong.”
– Dr. Rupak Mahapatra, SuperCDMS principal investigator, Texas A&M University
Advanced 6-inch silicon detectors developed by Mahapatra’s lab at Texas A&M
The collaboration will continue to probe this WIMP sector using the SuperCDMS Soudan experiment’s operating germanium detectors and is considering using larger, more advanced 6-inch silicon detectors developed at the Texas A&M’s Department of Electrical Engineering in future experiments.
The team has detailed its results in a paper published in arXiv that eventually will appear in Physical Review Letters. Mahapatra will also announce the results today at 12 p.m. CDT in a talk at the Mitchell Institute for Fundamental Physics and Astronomy.
