Sentences with word «reionization»
Reionization refers to a cosmic event that occurred in the early universe, where neutral hydrogen atoms were once again ionized (losing their electrons) by energetic radiation. This allowed the light from celestial objects to continue traveling freely, after a period in which the universe was filled with opaque ionized gas. Full definition
The final phase of reionization of the Universe may have occurred swiftly.
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Computer simulations of cosmic reionization suggest the Universe was fully opaque to Lyman - alpha radiation in the first 400 million years of cosmic history and then gradually, as the first galaxies were born, the intense ultraviolet radiation from their young stars, burned off this obscuring hydrogen in bubbles of increasing radius which, eventually, overlapped so the entire space between galaxies became «ionized», that is composed of free electrons and protons.
All three gamma - ray bursts (GRB 090423, 080913, and 050904) occurred during the Epoch of Reionization in the early universe.
Scientists believe that these observations could provide crucial insights into the scarcely understood reionization phase of the universe, and help understand the events that led to the birth of the first galaxies about 100 million years after the Big Bang.
We see indirectly the effect that the starlight would have had» on the cosmic environment, says Bowman, a collaborator on the Experiment to Detect the Global Epoch of Reionization Signature, EDGES, which detected the stars» traces.
HERA, which stands for Hydrogen Epoch of Reionization Array, will investigate a period in time when the very first generations of stars and galaxies formed, and totally altered the cosmic landscape.
Knowing when reionization kicks in will allow scientists to deduce precisely when the earliest stars flicked on.
«In any case, our next round of ALMA observations should help us understand how quickly these galaxies came together and improve our understanding of massive galaxy formation during reionization,» Marrone said.
Astronomers, therefore, look for signs of reionization by determining when 21 - centimeter emissions start to turn off — evidence that stars are, simultaneously, starting to turn on.
«It appears that the young stars in the early galaxies like EGS - zs8 - 1 were the main drivers for this transition, called reionization,» said Rychard Bouwens of the Leiden Observatory, co-author of the study.
Reionization made the universe transparent to light, allowing astronomers to look far back into time without running into a «fog» of cold hydrogen.
Through this series we are raising money for a Keck Cosmic Reionization Mapper which will enable new discoveries in the distant universe.
«Though the Epoch of Reionization took place deep in the universe's past, it lies at the very frontier of our current cosmological observations.
Astronomers plan to study the rise of the first stars and galaxies and the epoch of reionization with the successor to both the Hubble and Spitzer telescopes, NASA's James Webb Telescope, slated for launch in 2018.
For starters, Parsons and his collaborators are essentially looking at many single, two - dimensional slices of «Swiss cheese» and counting the number of holes to get a statistical measure of how patchy the cheese is — the number of holes indicating how far along reionization is.
That would provide a fuller picture, and chronology, of reionization throughout the cosmos.
Without any detailed observations of what reionization looked like, many models of the early universe «just kind of pick one time and say, «The universe is reionized now!»
That will give us details and insights into how long [reionization] took in a certain area and how big these areas were.»
If HERA succeeds, this radio telescope array in South Africa could reveal new information about the slow roast of universal reionization, the identities of the very first massive objects, the evolution of the cosmic ingredients list and perhaps even clues about the mechanism behind the formation of the first massive objects.
How reionization occurred is a fundamental question in astrophysics.
The observations peg the end of the epoch of reionization around 700 million years after the Big Bang, notes NASA.
Cosmic reionization started out as a flashlight revealing what was out in the darkness.
By studying reionization, we can learn a great deal about the process of structure formation in the universe, and find the evolutionary links between the remarkably smooth matter distribution at early times revealed by CMB studies, and the highly structured universe of galaxies and clusters of galaxies at redshifts of 6 and below.
The diagram below provides a good graphical representation of the history of the universe, and where the epoch of reionization sits in the overall picture.
So it's possible that the effort to understand the epoch of reionization just might help uncover a trove of habitable planets.
The goal of the HERA project is, most broadly, to trace those minute changes in hydrogen from about 100 million years after the Big Bang to one billion years after, when the epoch of reionization culminated with a conclusive turning on of the universe.
On 28 February, a group of astronomers working on the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) radio telescope found that as the first stars began to form, the gas around...
This is just the first step in understanding what caused cosmic reionization in the early universe.
Upcoming radio observations from the Low - Frequency Array, based mainly in the Netherlands, and the Hydrogen Epoch of Reionization Array — known as HERA — being built in South Africa could settle the question.
Some prior work suggested that massive stars were mostly responsible for reionization, but other research hinted that black holes were a significant, and potentially dominant, culprit behind this event.
«It appears that the young stars in the early galaxies like EGS - zs8 - 1 were the main drivers for this transition, called reionization,» said study co-author, Rychard Bouwens of the Leiden Observatory, Leiden, Netherlands.
Instruments now under development will further add to our leadership capabilities in astronomy, when in the next few years we bring to our science community the Keck Planet Finder (KPF) and the Keck Cosmic Reionization Mapper (KCRM).
Moreover, it also removes the need to invoke «exotic» and unknown sources to explain the process of reionization in the early universe.
Webb will also explore an era known as the Dark Ages and the time immediately following it, the period of reionization.
Parsons is co-principal investigator on the Precision Array to Probe the Epoch of Reionization (PAPER), a 128 - antenna telescope in South Africa's Karoo Desert.
The Precision Array to Probe the Epoch of Reionization will help pinpoint the earliest stars» births.
In addition to emitting visible light, the stars also gave off ultraviolet (UV) radiation, which split the neutral hydrogen it encountered into electrons and protons — ionizing it once again, and thereby launching what researchers call the «epoch of reionization.»
«The WMAP analysis placing the reionization at 420 million years after the big bang was a real puzzle,» says George Efstathiou, a University of Cambridge cosmologist and a leader of the Planck Collaboration.
One finalist, the Spectro - Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), will map galaxies across a large volume of the universe to find out what drove inflation, a pulse of impossibly fast expansion just after the big bang.
But the newly discovered objects may have kicked off the subsequent phase of reionization, in which ultraviolet starlight stripped electrons from hydrogen gas.
How has this important transformation, named cosmic reionization, been possible?
This era, when most of the hydrogen in the universe underwent a massive physical transformation, is known the epoch of reionization.
The reionization of hydrogen in the universe didn't occur like the flipping on of a light switch; it wasn't instantaneous and probably didn't happen at the same rate across the cosmos, said Anna Frebel, an assistant professor of physics at MIT who studies stars and galaxies that formed in the very early days of the universe.
The epoch of reionization was «probably more like the slow roast.
Further observations with Hubble will firm up this result and also help to better understand the photon «ejection» mechanism and the specific galaxy types driving cosmic reionization.