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York University and an international team of astrophysicists have made an ambitious attempt to simulate the formation of galaxies and cosmic large-scale structure throughout staggeringly large swaths of space.

First results of their MillenniumTNG project are published in a series of 10 articles in the journal Monthly Notices of the Royal Astronomical Society. The new calculations help to subject the standard cosmological model to precision tests and to unravel the full power of upcoming new cosmological observations, say the researchers including York Assistant Professor Rahul Kannan.

In recent decades, cosmologists have gotten used to the perplexing conjecture that the universe’s matter content is dominated by enigmatic dark matter and that an even stranger dark energy field that acts as some kind of anti-gravity to accelerate the expansion of today’s cosmos. Ordinary baryonic matter makes up less than five percent of the cosmic mix, but this source material forms the basis for the stars and planets of galaxies like our own Milky Way.

EMBARGO Wednesday 19 July 1,600 BST | 1,500 GMT | Thursday 20 July 100 AEST

Back when the Universe was still just a wee baby Universe, there wasn’t a lot going on chemically. There was hydrogen, with some helium, and a few traces of other things. Heavier elements didn’t arrive until stars had formed, lived, and died.

Imagine, therefore, the consternation of scientists when, using the James Webb Space Telescope to peer back into the distant reaches of the Universe, they discovered significant amounts of carbon dust, less than a billion years after the Big Bang.

“For decades Isaac Newton gave us this vision of a universe where space and time is fixed, and every clock across the universe ticks at exactly the same rate. Then Einstein shattered this vision by proposing that time is actually rubbery and relative,” says Geraint Lewis, an astrophysicist at the University of Sydney and lead author of the study. “Now we’ve shown that Einstein was, once again, correct.”

The Einsteinian concept of time running slower in the early universe arose in the late 1920s as astronomers were discovering cosmic expansion. Galaxies in the sky were found to be flying away from the Milky Way at high speed, swept along by the ceaselessly growing void—and the farther off they were, the faster they flew. This not only meant that the universe was once much smaller and denser—arising in a “big bang” from some compact, primordial point—but also that the most distant galaxies visible to us should be receding at close to the speed of light.

According to Einstein’s special and general theories of relativity, both circumstances alter the flow of time. As light from one of those far-distant galaxies travels from the heavier gravitational grip of the deep, dense early cosmos and across the continuously expanding universe, it must traverse increasingly greater expanses of space to reach Earth. Consequently, time becomes stretched in a phenomenon known as time dilation: a clock running 10 billion years ago would tick at a normal rate to an observer from that time, but from the perspective of someone today, it would appear to be ticking much slower.

“This gamma-ray burst was extremely bright. We expect to see one like this only every 10,000 years or so.”

A team of astronomers led by the University of Alabama in Huntsville has detected the brightest gamma-ray burst.

These bursts are thought to be among the most luminous explosions in the universe and created during the birth of black holes. GRBs generally last from less than a second to several minutes.

Continue reading “Three UAH researchers operating Gamma-ray Burst Monitor discover brightest gamma-ray burst ever detected” »

Teams of physicists worldwide have been trying to detect dark matter, an elusive type of matter that does not emit, absorb, or reflect light. Due to its lack of interactions with electromagnetic forces, this matter is very difficult to observe directly, thus most researchers are instead searching for signals originating from its interactions with other particles in its surroundings.

The PandaX experiment is a research effort dedicated to the search of dark matter using data collected by the Particle and Astrophysical xenon detector, situated at the China Jinping Underground Laboratory (CJPL) in Sichuan, in China. In a recent paper published in Physical Review Letters, the researchers involved in this large-scale experiment published the results of their most recent search for light dark matter (i.e., weakly interacting massive particles with masses below 1 GeV).

“Currently, strong constraints exist for heavy mass dark matter candidates derived from null results in direct detection experiments using xenon detectors,” Yue Meng, Qing Lin and Ning Zhou told Tech Xplore, on behalf of the PandaX collaboration. “However, traditional searches are not sensitive to light mass dark matter (less than GeV/c2) due to the detection energy threshold. Using an ionization-only signal (S2-only) to search for light mass dark matter can reduce the energy threshold from ~1 keV to 0.1 keV. Previous S2-only data analyses in xenon detectors were unable to model the background, which prevented effective and sensitive searches for light mass dark matter.”

The University of Alabama in Huntsville (UAH) has announced that three researchers associated with the UAH Center for Space Plasma and Aeronomic Research (CSPAR) have discovered a gamma-ray burst (GRB) approximately 2.4 billion light-years away in the constellation Sagitta that ranks as the brightest ever observed. Believed to have been triggered by collapse of a massive star, it is accompanied by a supernova explosion, giving birth to a black hole.

Dr. Peter Veres, an assistant professor with CSPAR, Dr. Michael S. Briggs, CSPAR principal research scientist and assistant director, and Stephen Lesage, a UAH graduate research assistant, collaborated on the discovery and analysis of the gamma-ray burst. The researchers operate the Gamma-ray Burst Monitor (GBM) at UAH, a part of the University of Alabama System.

The GBM is an instrument in low-Earth orbit aboard the Fermi Gamma-ray Space Telescope that can see the entire gamma-ray sky not blocked by the Earth and hunts for GRBs as part of its main program.

Scientists claim they’ve calculated a potential new method of time travel involving a theoretical object called a ring wormhole.’ Here are the details.

The James Webb Space Telescope has delivered yet another astounding discovery, spying an active supermassive black hole deeper into the universe than has ever been recorded.

The black hole lies within CEERS 1,019 — an extremely old galaxy likely formed 570 million years after the big bang — making it more than 13 billion years old. And scientists were perplexed to find just how small the celestial object’s central black hole measures.

“This black hole clocks in at about 9 million solar masses,” according to a NASA news release. A solar mass is a unit equivalent to the mass of the sun in our home solar system — which is about 333,000 times larger than the Earth.

The James Webb Space Telescope has delivered yet another astounding discovery, spying an active supermassive black hole deeper into the universe than has ever been recorded.

The black hole lies within CEERS 1,019 — an extremely old galaxy likely formed 570 million years after the big bang — making it more than 13 billion years old. And scientists were perplexed to find just how small the celestial object’s central black hole measures.

“This black hole clocks in at about 9 million solar masses,” according to a NASA news release. A solar mass is a unit equivalent to the mass of the sun in our home solar system — which is about 333,000 times larger than the Earth.