First indications of the neutrino fog—an important background for dark matter searches—from the PandaX & XENON collaborations Letters: https://go.aps.org/3AwVxQG & https://go.aps.org/3YSjX0l
Category: cosmology – Page 30
Hypothetical particles called axions could form dense clouds around neutron stars – and if they do, they will give off signals that radio telescopes can detect, say researchers in the Netherlands, the UK and the US. Since axions are a possible candidate for the mysterious substance known as dark matter, this finding could bring us closer to understanding it.
Around 85% of the universe’s mass consists of matter that appears “dark” to us. We can observe its gravitational effect on structures such as galaxies, but we cannot observe it directly. This is because dark matter hardly interacts with anything as far as we know, making it very difficult to detect. So far, searches for dark matter on Earth and in space have found no evidence for any of the various dark matter candidates.
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Detecting exploding primordial black holes from the universe’s first second may unveil new physics.
In that moment, pockets of hot material may have been dense enough to form black holes, potentially with masses ranging from 100,000 times less than a paperclip to 100,000 times more than the sun’s, according to scientists.
Then, as the universe quickly expanded and cooled, the conditions for forming black holes this way ended.
A black hole formula worked out in the 1970s remains the most concrete clue physicists have about the threads of the space-time fabric.
In a recent discovery, astronomers have found that the black hole in the well-known low-mass X-ray binary (LMXB) system V404 Cygni is part of a much larger structure—a wide triple system.
Many black holes detected to date appear to be part of a pair. These binary systems comprise a black hole and a secondary object — such as a star, a much denser neutron star, or another black hole — that spiral around each other, drawn together by the black hole’s gravity to form a tight orbital pair.
Now a surprising discovery is expanding the picture of black holes, the objects they can host, and the way they form.
In a study appearing today in Nature, physicists at MIT and Caltech report that they have observed a “black hole triple” for the first time. The new system holds a central black hole in the act of consuming a small star that’s spiraling in very close to the black hole, every 6.5 days — a configuration similar to most binary systems. But surprisingly, a second star appears to also be circling the black hole, though at a much greater distance. The physicists estimate this far-off companion is orbiting the black hole every 70,000 years.
Astronomers found the exhaust vent of a chimney at our galaxy’s center for the first time.
There is a supermassive black hole at the center of our galaxy that is nearly 17 times bigger than the Sun and can suck in over 1,800 Earths at once. This gigantic black hole goes by the name Sagittarius A* (Sgr A•.
In a new study, a team of researchers claims that Sgr A* has caused the formation of a chimney and an exhaust vent at the center of the Milky Way.
The study takes into account images from NASA’s Chandra X-Ray Observatory and radio emission data from the MeerKAT telescope, revealing that the vent attached to the chimney is expelling hot gases from our galaxy’s center.
Since its launch, the James Webb Space Telescope has identified early galaxies that shine unexpectedly brightly, suggesting rapid maturity and challenging current cosmological models.
The James Webb Space Telescope (JWST), the largest and most advanced space telescope ever constructed, has been making remarkable discoveries since its launch in December 2021. Among its achievements is the identification of the earliest and most distant galaxies known, which formed just 300 million years after the Big Bang.
When we observe distant objects in space, we are also looking far back in time. This is because the light from these objects takes billions of years to reach our telescopes. Through the JWST, astronomers have detected several of these ancient galaxies, providing us a glimpse of the universe as it appeared shortly after its inception.
This week, researchers reported the world’s second-tiniest toad, winning the silver in the Brachycephalus contest. Chemists at UCLA disproved a 100-year-old organic chemistry rule. And researchers in Kenya report that elephants don’t like bees, which could be a conservation boon (for the elephants. And maybe also the bees?). Additionally, scientists addressed an old thought experiment about monkeys and the theater, physicists correlated dark energy with the black hole population in the universe, and a group of Antarctic seals were found to be highly strategic and also adorable:
Astronomers have possibly found evidence that dark energy — associated with accelerating the expansion of our universe — could also be related with the mysterious black holes.
About 70% of our universe roughly comprises of dark energy and is believed to have born after the Big Bang, around 13.8 billion years ago, though the origin of the force remains unclear, according to LiveScience.
Recently, some astronomers proposed a theory that dark energy could have emerged from the core of gigantic dark abyss called the black holes while others disagreed with the theory.
“We can now see the moment where atomic nuclei and electrons are uniting in the afterglow,” team member Rasmus Damgaard, a researcher at the Cosmic DAWN Center, said in a statement. For the first time, we see the creation of atoms, we can measure the temperature of the matter, and we can see the microphysics in this remote explosion.”
“It is like admiring three cosmic background radiation surrounding us from all sides, but here, we get to see everything from the outside. We see before, during, and after the moment of birth of the atoms.”
Neutron stars are born when stars at least 8 times as massive as the sun exhaust their fuel for nuclear fusion and can no longer support themselves against their own gravity.