A galactic magnetic field in a lab bolsters astrophysical theory
physorg.com
Since the 1950’s, an German astronomer predicts (what is known as the Biermann battery process)that a magnetic field can spring up spontaneously from nothing more than the motion of charged particles. In space, plasma (charged particles) is abundant.
With the use high-energy pulsed lasers, researchers can create certain conditions analogous to those in the early universe when galaxies were forming. Through their experiment, they demonstrated that the theory is likely correct.
From that experiment, scientist believe during the collapsing of galaxies, large clouds of gas send an elliptical bubble-shaped shockwave through the early universe. That shockwave is like a flow of electric current zipping through the cosmos. That experiment demonstrated that such shockwaves can do the job… electric current in the plasma developing magnetic fields. Very cool!
Early Stars Created A Sight Yet Unseen - Science News
sciencenews.orgEvidence could someday be detected by radio telescopes, study suggests
Powerful X-ray jet detected in very early galaxy
chandra.harvard.edu
A jet of X-rays from a supermassive black hole 12.4 billion light years from Earth has been detected by NASA’s Chandra X-ray Observatory. This is the most distant X-ray jet ever observed and gives astronomers a glimpse into the explosive activity associated with the growth of supermassive black holes in the early universe.
The jet was produced by the quasar GB 1428+4217. Supermassive black holes at the centers of galaxies can pull in matter at a rapid rate, producing the quasar phenomenon. The energy released as particles fall toward the black hole generates intense radiation and powerful beams of high-energy particles that are driven from the black hole at nearly the speed of light. These particle beams can interact with magnetic fields or ambient photons to produce jets of radiation.
As the electrons in the jet fly away from the quasar, they move through cosmic microwave background photons. When a fast-moving electron collides with one of these photons, it can boost the photon’s energy into the X-ray band. “Since the brightness of the jet in X-rays depends, among other things, on how fast the electrons are moving away from the black hole, discoveries like the jet in GB 1428 tell us something about the environment around supermassive black holes and their host galaxies not that long after the Big Bang,” said research co-author Lukasz Stawarz. Because the quasar is seen when the universe was at an age of about 1.3 billion years, the cosmic background radiation around GB 1428 is a thousand times more intense than it is now. This makes the jet much brighter. While another possible source of X-rays for the jet is radiation from electrons spiraling around magnetic field lines in the jet, the researchers favor the idea that the cosmic background radiation is being boosted, because the jet is so bright.
The particle beams that produce these three extremely distant X-ray jets appear to be moving slightly more slowly than jets from less distant galaxies. This may be because the jets were less energetic when launched from the black hole or because they are slowed down more by their environment. The researchers think the length of the jet in GB 1428 is at least 230,000 light years. This jet is only seen on one side of the quasar in the Chandra and VLA data. When combined with previously obtained evidence, this suggests the jet is pointed almost directly toward us. This configuration would boost the X-ray and radio signals for the observed jet.
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Hubble census finds galaxies at redshifts 9 to 12
spacetelescope.org
Astronomers using the NASA/ESA Hubble Space Telescope have found seven primitive galaxies from a distant population that formed more than 13 billion years ago. In the process, their observations have put forward a candidate for the record for the most distant galaxy found to date (at redshift 11.9), and have improved understanding of the earliest years of cosmic history. The galaxies are seen as they were when the universe was less than 4% of its present age. The new images offer the deepest ever view of the universe at near-infrared wavelengths, which capture the redshifted light of early galaxies. Astronomers are looking back in time, seeing these galaxies as they appeared 600 million years after the Big Bang. One object spotted may be the most distant ever observed.
The new data have allowed the team to uncover six previously-unknown galaxies in this era, and to rule out a number of tentative identifications of distant galaxies made by other scientists in previous research. This is the first statistically robust census of galaxies at such an early time in cosmic history, and shows that the number of galaxies steadily increased with time, supporting the idea that the first galaxies didn’t form in a sudden burst but gradually assembled their stars.
One previously-claimed candidate extreme redshift galaxy in the Hubble Ultra Deep Field was confirmed by the team. This is UDFj-39546284, for a while claimed to be the most distant known galaxy, at redshift 10. However, the improved and extended dataset has allowed the scientists to show that it either lies at an even greater distance than previously thought (at a redshift of 11.9, handing it back the distance record), or must otherwise be a previously unknown type of extreme emission-line galaxy at much lower redshift.
“Our study has taken the subject forward in two ways,” said research co-leader Richard Ellis. “First, we have used Hubble to make longer exposures than previously. The added depth is essential to reliably probe the early period of cosmic history. Second, we have used Hubble’s available color filters very effectively to measure galaxy distances more precisely.”
More:
• Galaxy found at record-breaking distance
• Hubble sees earliest known galaxies through cosmic fog
• Caltech-led astronomers discover galaxies near cosmic dawn
• NASA’S Hubble Provides First Census of Galaxies Near Cosmic Dawn
• Six new galaxies and ‘probably’ the most distant galaxy to date
• Hubble Comes Close to Spying First Stars
• Hubble spots oldest, furthest galaxies
• Hubble spies galaxies from baby universe
• Clutch of distant galaxies reveals the infant universe
• Hubble Images Reveal 7 of the Most Distant Galaxies Ever Seen
• Seven Of Furthest, Most Ancient Galaxies Discovered With Hubble Space Telescope
• Hubble Takes Galaxy Census
Surprisingly early starburst galaxies found
eso.orgObservations with the Atacama Large Millimeter/submillimeter Array (ALMA) show that the most vigorous bursts of star birth in the universe occurred much earlier than previously thought. The most intense bursts of star birth are thought to have occurred in the early universe, in massive, bright galaxies. These starburst galaxies convert vast reservoirs of cosmic gas and dust into new stars very rapidly — many hundreds of times faster than in spiral galaxies like the Milky Way.
The international team of researchers first discovered these distant starburst galaxies with the 10-meter South Pole Telescope (SPT) and then used ALMA to examine them in more detail. They were surprised to find that many of these distant, dusty, star-forming galaxies are even further away than expected. So on average their bursts of star birth took place when the universe was just under 2 billion years old — a full billion years earlier than previously thought. Two of these galaxies are the most distant of their kind ever seen — so they are seen at a time the universe was only one billion years old.
The team used ALMA to capture light from 26 of these galaxies at wavelengths of around three millimeters. Astronomers took advantage of gravitational lensing, an effect predicted by the general theory of relativity, where light from a distant galaxy is distorted by the gravitational influence of a nearer foreground galaxy, which acts like a lens and makes the distant source appear brighter. To understand how much this gravitational lensing brightened the view of the galaxies, the team made sharper images of them using more ALMA observations at wavelengths of around 0.9 millimeters.
Analysis of the gravitational lensing distortion shows that some of the distant star-forming galaxies are as bright as 40 trillion Suns, and that gravitational lensing has magnified this by up to 22 times. “Only a few gravitationally lensed galaxies have been found before at these submillimeter wavelengths, but now SPT and ALMA have uncovered dozens of them.” said team member Carlos De Breuck.
More:
• ALMA finds ‘monster’ starburst galaxies in the early universe
• Ancient, highly active galaxies discovered
• ALMA exposes hidden star factories in the early universe
• ‘Nuisance’ data lead to surprising star-birth discovery
• Bursts of star formation in the early universe
• NSF-funded Telescopes in Antarctica and Chile Discover Bursts of Star Formation in the Early Universe
• Gravitational lensing - and a new telescope - reveal ancient starbursts
• Witnessing Starbursts in Young Galaxies
GigaPan Time Machine: Early Universe
timemachine.gigapan.orgThis is a timelapse that shows the distribution of matter in a simulated universe on large scales.
