International team strengthens Big Bang Theory

(Phys.org) —An international team of scientists using the most powerful telescope on Earth has discovered the moments just after the Big Bang happened more like the theory predicts, eliminating a significant discrepancy that troubled physicists for two decades. The discovery will be published in the international journal Astronomy & Astrophysics on June 6.

One of the most important problems in physics and astronomy was the inconsistency between the lithium isotopes previously observed in the oldest stars in our galaxy, which suggested levels about two hundred times more Li-6 and about three to five time less Li-7 than Big Bang nucleosynthesis predicts. This serious problem in our understanding of the early Universe has invoked exotic physics and fruitless searches for pre-galactic production sources to reconcile the differences.

The team, led by Karin Lind of the University of Cambridge, has proven the decades-old inventory relied on lower quality observational data with analysis using several simplifications that resulted in spurious detections of lithium isotopes.

Using observations of ancient stars with W. M. Keck Observatory’s 10-meter telescope and state-of-the-art models of their atmospheres has shown that there is no conflict between their lithium-6 and lithium-7 content and predictions of the standard theory of Big Bang nucleosynthesis, restoring thus the order in our theory of the early universe.

The discovery that the universe was expanding by Edwin Hubble in the 1920s and subsequent observations suggest the universe began about 13.8 billion years ago in an event called the Big Bang. The fundamental observations that corroborate the Big Bang are the cosmic microwave radiation and the chemical abundances of the light elements described in the Big Bang nucleosynthesis theory.

“The predictions of Big Bang nucleosynthesis have been one of the main successes of the standard Big Bang model,” said lead author Lind. “Our findings remove much of the stark tension between 6Li and 7Li abundances in stars and standard BBN, even opening up the door for a full reconciliation. This further consolidates a model resting heavily on the pillars of the cosmic microwave background and the expanding Universe.”

Taking accurate measurements of lithium-6 and lithium-7 in old stars is extremely challenging, both from a theoretical and observational perspective, in particular for lithium-6, because being the less abundant isotope of lithium, its signature is very weak. The required data can only be obtained with the largest telescopes on Earth such as the Keck Observatory on the summit of Mauna Kea, Hawaii equipped with the powerful High Resolution Echelle Spectrometer (HIRES) spectrograph to disperse the stellar light into its constituent colors and absorption features.

“Back in 2004 HIRES was upgraded with CCDs having smaller pixels, allowing to see finer details in the spectrum,” University of Sao Paulo’s Jorge Meléndez said. “A high spectral resolution provided by HIRES is needed to study with exquisite detail the line profile and to estimate the presence of Lithium-6. The large light-collecting power of Keck Observatory allowed us to observe stars with a more ‘pristine’ composition than any previous study.”

Even with the mighty Keck I telescope, a single star must be observed for several hours to gather enough photons for a detailed observation. The modeling of such data is also very demanding, as different processes in the atmospheres of such metal-deficient old stars may mimic the presence of lithium-6. The data must be analyzed using sophisticated model atmospheres created by the team in 3D and included complex calculations that run for weeks on powerful super computers.

“We simultaneously relaxed two key physical assumptions in the modeling of stellar atmospheres; one-dimensional hydrostatic and local thermodynamic equilibrium,” Lind said. “Using more sophisticated physics and powerful super-computers, we managed to remove the systematic biases that plague traditional modeling and have previously led to false identifications of the 6Li/7Li isotopic signature.”

The synergy of high quality Keck observations and detailed theoretical modeling has solved cosmological problems that haunted particle physicists and astrophysicists during the last two decades.

“Understanding the birth of our Universe is pivotal for the understanding of the later formation of all its constituents, ourselves included,” Lind said. “The Big Bang model sets the initial conditions for structure formation and explains our presence in an expanding universe dominated by dark matter and energy.”

The Big Bang theory now rests on more firm footing.

Explore further: Theorists apply loop quantum gravity theory to black hole

More information: Lind, K. et al. The lithium isotopic ratio in very metal-poor stars, Astronomy & Astrophysics. dx.doi.org/10.1051/0004-6361/201321406

http://phys.org/news/2013-06-international-team-big-theory.html

via astrodidact

Chandra, Spitzer Study Suggests Black Holes Abundant Among the Earliest Stars

By comparing infrared and X-ray background signals across the same stretch of sky, an international team of astronomers has discovered evidence of a significant number of black holes that accompanied the first stars in the universe.

Using data from NASA’s Chandra X-ray Observatory and NASA’s Spitzer Space Telescope, which observes in the infrared, researchers have concluded one of every five sources contributing to the infrared signalis a black hole.

Continue Reading

via thenewenlightenmentage

Space Sounds - Sounds of the Big Bang

It’s time for another Episode Extra! (which is where you special blog readers get to check out really cool stuff to go along with my YouTube videos, like special features on a DVD, only way more special-er)

I’ve got another extra feature to go along with my latest Space Sounds video! I’m full of ‘em this week.

The very first radiation to escape after the Big Bang has been traveling outward for 13.8 billion years. This cosmic microwave background has been literally stretched over time, it’s frequency and temperature lowering as the universe, and everything in it, expands.

John G. Cramer from the University of Washington took the measurement data of the cosmic microwave background from ESA’s Planck space telescope and converted the energy frequencies of the first 760,000 years of the universe into audible sound. He had to multiply each frequency by 10^26 so we could hear it!

More “space sounds” episode extras here. Click here to subscribe on YouTube!

via jtotheizzoe

(via skeptv)

Detection of the cosmic gamma ray horizon measures all the light in the universe since the Big Bang

How much light has been emitted by all galaxies since the cosmos began? After all, almost every photon (particle of light) from ultraviolet to far infrared wavelengths ever radiated by all galaxies that ever existed throughout cosmic history is still speeding through the Universe today. If we could carefully measure the number and energy (wavelength) of all those photons—not only at the present time, but also back in time—we might learn important secrets about the nature and evolution of the Universe, including how similar or different ancient galaxies were compared to the galaxies we see today.

That bath of ancient and young photons suffusing the Universe today is called the extragalactic background light (EBL). An accurate measurement of the EBL is as fundamental to cosmology as measuring the heat radiation left over from the Big Bang (the cosmic microwave background) at radio wavelengths. A new paper, called “Detection of the Cosmic γ-Ray Horizon from Multiwavelength Observations of Blazars,” by Alberto Dominguez and six coauthors, just published today by the Astrophysical Journal—based on observations spanning wavelengths from radio waves to very energetic gamma rays, obtained from several NASA spacecraft and several ground-based telescopes—describes the best measurement yet of the evolution of the EBL over the past 5 billion years.

Read More.

(Source: christinetheastrophysicist)

scienceisbeauty:

John G. Cramer, a professor emeritus at the University of Washington, Seattle, has taken the new, highly detailed data from the European Space Agency’s Planck mission, which measures CMB, and run them through Mathematica software to convert the CMB measurements into an audio simulation of the universe’s first 760,000 years (an extremely brief period on a cosmological scale).

Source: Is This What the Big Bang *Sounded* Like? (The Atlantic)

electricspacekoolaid:

Supercomputer Helps Planck Mission Expose Ancient Light

Image: The bulk of the Planck computations were performed on the Cray XE6 supercomputer, named for computer scientist Grace Hopper, at the Department of Energy’s National Energy Research Scientific Computing Center at the Lawrence Berkeley National Laboratory, Berkeley, Calif. 

Like archeologists carefully digging for fossils, scientists with the Planck mission are sifting through cosmic clutter to find the most ancient light in the universe.

The Planck space telescope has created the most precise sky map ever made of the oldest light known, harking back to the dawn of time. This light, called the cosmic microwave background, has traveled 13.8 billion years to reach us. It is so faint that Planck observes every point on the sky an average of 1,000 times to pick up its glow.

The task is even more complex than excavating fossils because just about everything in our universe lies between us and the ancient light. Complicating matters further is “noise” from the Planck detectors that must be taken into account.

That’s where a supercomputer helps out. Supercomputers are the fastest computers in the world, performing massive amounts of calculations in a short amount of time.

“So far, Planck has made about a trillion observations of a billion points on the sky,” said Julian Borrill of the Lawrence Berkeley National Laboratory, Berkeley, Calif. “Understanding this sheer volume of data requires a state-of-the-art supercomputer.”

Planck is a European Space Agency mission, with significant contributions from NASA. Under a unique agreement between NASA and the Department of Energy, Planck scientists have been guaranteed access to the supercomputers at the Department of Energy’s National Energy Research Scientific Computing Center at the Lawrence Berkeley National Laboratory. The bulk of the computations for this data release were performed on the Cray XE6 system, called the Hopper. This computer makes more than a quintillion calculations per second, placing it among the fastest in the world.

One of the most complex aspects of analyzing the Planck data involves the noise from its detectors. To detect the incredibly faint cosmic microwave background, these detectors are made of extremely sensitive materials. When the detectors pick up light from one part of the sky, they don’t reset afterwards to a neutral state, but instead, they sort of buzz for a bit like the ringing of a bell. This buzzing affects observations made at the next part of the sky.

Read

abluegirl:

The Planck cosmic recipe.

Planck Shows Almost Perfect Cosmos – Plus Axis Of Evil

The universe is almost perfect, 80 million years older than we thought, and maybe a little bit evil.

That’s the conclusion of a four-year mission conducted by the European Space Agency’s Planck spacecraft, which has created the highest-resolution map yet of the entire cosmic microwave background (CMB) – the first light to travel across a newly transparent universe about 380,000 years after the big bang.

“It might look like a dirty rugby ball or a piece of modern art, but I can assure you cosmologists would have hacked our computers or given up their children to get a copy of this map,” said George Efstathiou at a press conference at ESA headquarters in Paris, France, this morning.

Planck’s map greatly improves cosmologists’ understanding of the universe, but it does not solve lingering mysteries over unusual patterns in the CMB. These include a “preferred” direction in the way the temperature of the light varies, dubbed the cosmic “axis of evil”, as well as an inexplicably cold spot that could be evidence for universes beyond our own (see image, above).

Planck has been looking for variations in the temperature of the CMB, which emerged at around 3000 kelvin, but by now has cooled to just a few degrees above absolute zero, on average.

Virtual trip
These variations are thought to have arisen from tiny, quantum fluctuations in the very early universe that were stretched out to massive scales during a brief period of accelerated expansion known as inflation. This occurred only 10-34 seconds after the big bang and seeded the distribution of stars and galaxies we see today. The CMB lets cosmologists probe this initial stage, taking them on a “virtual trip to the origins of the universe”, said ESA director general Jean Jacques Dordain.

By analysing the statistical properties of the map, cosmologists can compare their best models for inflation with the universe that we can observe today. The high-resolution results from Planck show very strong agreement with cosmological theory. “The overall conclusion is that standard cosmology is an extremely good match to Planck data,” said Efstathiou. “If I were an inflationary theorist I would be extremely happy.”

Cosmologists can’t pack up and go home just yet though, as Planck’s map has also confirmed the presence of a mysterious alignment of the universe. The “axis of evil” was identified by Planck’s predecessor, NASA’s Wilkinson Microwave Anisotropy Probe (WMAP).

The pattern of hot and cold variations in the CMB should be randomly distributed – and they are when comparing small patches of the universe. At larger scales, however, Planck reveals that one half of the universe has bigger variations than the other. Planck’s detectors are over 10 times more sensitive and have about 2.5 times the angular resolution of WMAP’s, giving cosmologists a much better look at this alignment. “We can be extremely confident that these anomalies are not caused by galactic emissions and not caused by instrumental effects, because our two instruments see very similar features,” said Efstathiou.

Bruised cosmos
Planck has also confirmed WMAP’s detection of a large unexplained cold spot in the CMB, which some cosmologists took as a sign that there are universes beyond our own. One model of inflation, called eternal inflation, suggests that new universes are continually popping into existence and expanding. This expansion could cause another universe to collide with ours, creating a “bruise” that would show up as a cold spot in the sky.

These anomalies are sure to be debated for many years to come now that cosmologists have a new source of data. Planck scientists have already used their measurements to refine the speed at which the universe is expanding, described by a parameter called the Hubble constant. The new value means that a galaxy roughly 1 million light years away is moving away from us at 20.59 kilometres per second – less than the current value. The result in turn puts the age of the universe at around 13.82 billion years, roughly 80 million years older than previously thought.

Planck’s results also adjust the relative proportions of ordinary matter and the mysterious dark matter and dark energy thought to make up the bulk of the cosmos – the universe has slightly more matter and dark matter and slightly less dark energy than we thought (see graph). “There is less stuff that we don’t understand, by a tiny amount,” said Efstathiou.

Hawking graffiti
One observation that will leave many particle physicists disappointed is the lack of any evidence for a fourth variety of neutrino. We know there are three kinds of these ghostly particles, which barely interact with ordinary matter – the electron, muon and tau neutrinos. Measurements from WMAP allowed for the existence of either three or four types of neutrinos, but Planck’s more detailed data places the number firmly in the three camp.

The spacecraft’s revelations aren’t over yet though. Today’s results are based on the first 15½ months of Planck’s scans, and there is a similar amount of data to follow in the future. ESA has also yet to release information about the polarisation of the CMB, which will provide an additional view of the cosmic pattern. “To paraphrase Arnold Schwarzanegger, we’ll be back,” said Efstathiou.

Finally, in case you were wondering: After the WMAP team pointed out that Stephen Hawking’s initials were visible in their map - we took a look at the new Planck map, and can reveal that the distinctive “SH” is still there.

invaderxan:

Acquired by ESA’s Planck space telescope, the most detailed map ever created of the cosmic microwave background – the relic radiation from the Big Bang – was released today revealing the existence of features that challenge the foundations of our current understanding of the Universe.

Picture of the Big Bang (a.k.a. Oldest Light in the Universe)
via minutephysics

distant-traveller:

WMAP team releases final results, based on nine years of observations

Since its launch in 2001, the Wilkinson Microwave Anisotropy Probe (WMAP) space mission has revolutionized our view of the universe, establishing a cosmological model that explains a widely diverse collection of astronomical observations. Led by Johns Hopkins astrophysicist Charles L. Bennett, the WMAP science team has determined, to a high degree of accuracy and precision, not only the age of the universe, but also the density of atoms; the density of all other non-atomic matter; the epoch when the first stars started to shine; the “lumpiness” of the universe, and how that “lumpiness” depends on scale size.

WMAP’s “baby picture of the universe” maps the afterglow of the hot, young universe at a time when it was only 375,000 years old, when it was a tiny fraction of its current age of 13.77 billion years. The patterns in this baby picture were used to limit what could have possibly happened earlier, and what happened in the billions of year since that early time. The “big bang” framework of cosmology, which posits that the young universe was hot and dense, and has been expanding and cooling ever since, is now solidly supported, according to WMAP.

WMAP observations also support an add-on to the big bang framework to account for the earliest moments of the universe. Called “inflation,” the theory says that the universe underwent a dramatic early period of expansion, growing by more than a trillion trillion-fold in less than a trillionth of a trillionth of a second. Tiny fluctuations were generated during this expansion that eventually grew to form galaxies.

Remarkably, WMAP’s precision measurement of the properties of the fluctuations has confirmed specific predictions of the simplest version of inflation: the fluctuations follow a bell curve with the same properties across the sky, and there are equal numbers of hot and cold spots on the map. WMAP also confirms the predictions that the amplitude of the variations in the density of the universe on big scales should be slightly larger than smaller scales, and that the universe should obey the rules of Euclidean geometry so the sum of the interior angles of a triangle add to 180 degrees.

The universe comprises only 4.6 percent atoms. A much greater fraction, 24 percent of the universe, is a different kind of matter that has gravity but does not emit any light—called “dark matter”. The biggest fraction of the current composition of the universe, 71%, is a source of anti-gravity (sometimes called “dark energy”) that is driving an acceleration of the expansion of the universe.

Image credit: NASA / WMAP Science Team

we-are-star-stuff:

Astronomers have released a new “baby picture” of the universe.

The all-sky image draws on nine years’ worth of data from a now-retired spacecraft dubbed the Wilkinson Microwave Anisotropy Probe (WMAP). WMAP launched in 2001 and from its perch a million miles away from Earth (in the direction opposite the sun) it scanned the heavens, mapping out the afterglow of the hot, young universe with unprecedented accuracy.

“We are just a speck in the vastness of the universe, so it is amazing that we have the ability to answer fundamental questions about the vast universe around us, but the WMAP team has done just that,” says Charles Bennett, an astrophysicist at Johns Hopkins University who heads the team. “It was possible because we can detect and study the ancient light, the oldest light in the universe.”

The image maps the temperature of the radiation left over from the Big Bang, at a time when the universe was only 375,000 years old. It shows a temperature range of plus-or-minus 200 microKelvin, with fluctuations in the so-called cosmic microwave background radiation appearing here as color differences.

These patterns allow astronomers to predict what could have possibly happened earlier, and what has happened in the billions of year since the universe’s infancy. As such, the spacecraft has been instrumental in pushing forward cosmological theories about the nature and origin of the universe.

Among other revelations, the data from WMAP revealed a much more precise estimate for the age of the universe — 13.7 billion years — and confirmed that about 95 percent of it is composed of mind-boggling stuff called dark matter and dark energy. WMAP data also helped scientists nail down the curvature of space to within 0.4 percent of “flat,” and pinpoint the time when the universe began to emerge from the cosmic dark ages (about 400 million years after the Big Bang.)

“The universe encoded its autobiography in the microwave patterns we observe across the whole sky,” Bennett said in a statement. “When we decoded it, the universe revealed its history and contents. It is stunning to see everything fall into place.”

jtotheizzoe:

A view from before the beginning of time … 

Confused? Start here.

Light From Universe’s First Stars Seen

Image 1: Ultraviolet and visible light emitted by all the stars that ever existed is still coursing through the universe. Astronomers refer to this “fog” of starlight as the extragalactic background light (EBL). Image released Nov. 1, 2012.
CREDIT: NASA’s Goddard Space Flight Center

Image 2: Gamma rays interact with the EBL, which gives astronomers a means to probe the stellar content of the cosmos. Image released Nov. 1, 2012.
CREDIT: NASA’s Goddard Space Flight Center

Image 3: This plot shows the locations of 150 blazars (green dots) used in the EBL study. Image released Nov. 1, 2012.
CREDIT: NASA/DOE/Fermi LAT Collaboration

Astronomers have spotted light from the very first stars in the universe, which are almost as old as time itself.

Shortly after the Big Bang 13.7 billion years ago, the universe cooled enough to let atoms form, which eventually clumped together to create the first stars. Ever since these stars ignited, their light has been filling the universe, creating a pervasive glow throughout space that each successive generation of stars adds to.

Now, astronomers have detected this glow — called the extragalactic background light, or EBL — and have separated out the light from later stars, isolating the contribution from the first stars that ever existed.

“The EBL is the ensemble of photons generated by all the stars and also all the black holes in the universe,” said astrophysicist Marco Ajello of the SLAC National Accelerator Laboratory in California, who led the research. “The EBL also includes the light of the first massive stars that ever shone. We have a fairly good knowledge of the light emitted by ‘normal’ stars. Thus, by measuring the EBL we are able to constrain the light of the first stars.”

Ajello and his team did not measure the EBL directly, but they detected it by analyzing measurements of distant black holes made by NASA’s Fermi Gamma-Ray Space Telescope. Fermi studied light from objects called blazars, which are giant black holes that release copious amounts of light while gobbling up large meals of matter.

“We use [blazars] as cosmic lighthouses,” Ajello said. “We observe their dimming due to the EBL ‘fog’. This allows us to quantify how much EBL there is between us and the blazars. As blazars are distributed across the universe, we can measure the EBL at different epochs.”

The study was able to probe light emitted by stars that existed when the universe was just 0.6 billion years old or so — relatively an infant.

These first stars are thought to have been quite different from stars that form today. In general, they were much more massive, containing up to hundreds of times the mass of our sun, and burned hotter, brighter, and for shorter lifetimes than stars today. [Gallery: History & Structure of the Universe]

The new measurements should help astronomers answer some of their most basic questions about the first generations of stars, such as how quickly they formed, and how soon after the birth of the universe the first stars came to be, researchers said.

“We really need to understand this period,” said Volker Bromm, an astronomer at the University of Texas at Austin who did not participate in the research, during a NASA press conference announcing the results. “At this point we have theoretical models, but we need to test them and constrain them.”

“With Fermi we have the first step into this cosmic frontier,” Bromm added.

Already, the scientists have found that the first stars’ peak formation rate must have been lower than previously thought.

Ultimately, the researchers would like to constrain this parameter further, and eventually to glimpse these ancient stars themselves. Future technology, such as NASA’s successor to the Hubble Space Telescope, called the James Webb Space Telescope (expected to come online by 2018), should come closer to doing the job.

“Detecting these stars is very important, but currently impossible,” Ajello said. “The Webb Telescope in a few years might be able to see the first galaxies (not the first stars though). In this way we are already able to set constraints on the amount and role of these stars in the early universe.”

The findings are reported in the Nov. 2 issue of the journal Science.

NASA to Announce Early Universe Findings Thursday

Image: Artist’s illustration of NASA’s Fermi Gamma-ray Space Telescope.
CREDIT: NASA

NASA is planning to announce a discovery from its Fermi Gamma-ray Space Telescope on Thursday (Nov. 1) that will shed light on the early universe, officials said.

The announcement will “discuss new measurements using gamma rays to investigate ancient starlight,” NASA officials said in a statement today (Oct. 29). The findings, which will be published in the Nov. issue of the journal Science, will be revealed during a teleconference Thursday at 2 p.m. EDT (1800 GMT).

Participants in the teleconference include:

Justin Finke, an astrophysicist at the Naval Research Laboratory, Washington
Marco Ajello, an astrophysicist at the Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, and the Space Sciences Laboratory at the University of California at Berkeley
Volker Bromm, an associate professor in the department of astronomy at the University of Texas at Austin

The Fermi telescope launched in June 2008, and has been probing the sky in short-wavelength, high-energy gamma-ray light ever since. The observatory is named after Italian physicist Enrico Fermi, winner of the 1938 Nobel Prize in physics for his work on radioactive elements. He was a pioneer of high-energy physics, the domain of the Fermi telescope.