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Archive for the ‘cosmology’ category: Page 65

Mar 9, 2024

Supermassive black hole is most distant ever found, as Webb telescope “unlocks secrets” of far-away galaxy

Posted by in category: cosmology

Two teams of researchers studying a galaxy through NASA’s James Webb Space Telescope have made multiple discoveries, including spotting the most distant active supermassive black hole ever found.

The teams were studying a galaxy known as GN-z11, an “exceptionally luminous” system that was formed when our 13.8 billion-year-old universe was only about 430 million years old, making it one of the youngest ever observed, NASA said in a news release. Scientists have been trying to find out what makes the distant galaxy so bright, and in doing so discovered the far-off black hole and a gas clump that could indicate rare stars.

The black hole was found by researchers from the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge in the United Kingdom using the telescope’s near-infrared camera. They determined the structure was a supermassive black hole, the largest type of black hole. It’s the most distant black hole of this size ever seen.

Mar 9, 2024

Physicists are reimagining dark matter

Posted by in categories: cosmology, evolution, physics

Dr Freese has also made the case for a Dark Big Bang that could have given rise to dark matter independently of normal matter in the days after the Big Bang. The traditional model of the universe says that matter and dark matter were produced at the same time. The earliest evidence of dark matter, however, only appears later in the early evolution of the universe, when cosmic structure starts to form.

One explanation for this is that matter and dark matter did not, in fact, appear together, but that dark matter entered the universe in a second cataclysmic release of energy from the vacuum—the Dark Big Bang—as much as a month after the traditional Big Bang. The model that Dr Freese and her co-author Martin Winkler explored would explain why dark matter might be completely decoupled from traditional matter and it also naturally produces SIDM candidates. If there was such a Dark Big Bang, it would have left a clear signature—a pattern in the frequencies of the gravitational waves that hum across the universe—that could be picked up by future gravitational-wave detectors.

Mar 9, 2024

Beam balance designs could elucidate the origins of dark energy

Posted by in categories: cosmology, physics

One of the greatest problems in modern physics is to reconcile the enormous difference between the energy carried by random fluctuations in the vacuum of space, and the dark energy driving the universe’s expansion.

Through new research published in The European Physical Journal Plus, researchers led by Enrico Calloni at the University of Naples Federico II, Italy, have unveiled a prototype for an ultra-precise balance instrument, which they hope could be used to measure the interaction between these vacuum fluctuations and gravitational fields. With some further improvements, the instrument could eventually enable researchers to shed new light on the enigmatic origins of .

Inside a vacuum, are constantly emerging and disappearing through random fluctuations, so that even though the space doesn’t contain any matter, it still carries a certain amount of energy. Through their research, Calloni’s team aimed to measure the influence of these fluctuations using a state-of-the-art beam balance.

Mar 9, 2024

Neutron star mergers: New physics signals

Posted by in categories: cosmology, particle physics

There is reason to believe that novel physics outside the standard model may be on the horizon.

When two neutron stars merge, a short-lived, hot, dense remnant is created. This residue provides an excellent environment for the synthesis of unusual particles. For a brief while, the remnant becomes far hotter than the individual stars before congealing into a larger neutron star or, depending on the original masses, a black hole.

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Mar 9, 2024

Astronomers Observe the Effect of Dark Matter on the Evolution of the Galaxies

Posted by in categories: cosmology, evolution

Dark matter comprises around 85% of all the matter in the universe. Although ordinary matter absorbs, reflects and emits light, dark matter cannot be seen directly, which makes its detection difficult. Its existence is inferred from its gravitational effects on visible matter, the material that forms stars, planets, and other objects in the cosmos.

Galaxies are made up of these two types of material The dark matter is distributed in halos, which are huge structures surrounding galaxies, while the ordinary matter is mainly present in the central regions where most of the stars are found.

Traditionally observational studies of galactic evolution have centered on the role of ordinary matter, even though it is quite a small fraction of the mass of a galaxy. For decades there have been theoretical predictions about the effect that dark matter should have on the evolution of galaxies. However, in spite of numerous efforts, there is no clear consensus about this.

Mar 9, 2024

Observations Explore Radio Jet of a Powerful Quasar

Posted by in categories: cosmology, physics

European astronomers have conducted very long baseline interferometric (VLBI) observations of a radio jet structure in a powerful quasar known as PKS 2215+020. The collected VLBI data provide important insights into the properties of this jet, suggesting that PKS 2215+020 is a blazar. The findings were presented February 17 in the Universe journal.

Quasars, or quasi-stellar objects (QSOs) are active galactic nuclei (AGN) of very high luminosity, emitting electromagnetic radiation observable in radio, infrared, visible, ultraviolet and X-ray wavelengths.

They are among the brightest and most distant objects in the known universe, and serve as fundamental tools for numerous studies in astrophysics as well as cosmology. For instance, quasars have been used to investigate the large-scale structure of the universe and the era of reionization. They also improve our understanding of the dynamics of supermassive black holes and the intergalactic medium.

Mar 9, 2024

The Bizarre Mystery of White Holes

Posted by in categories: cosmology, physics, space travel

An exploration of the inverse of a black hole, a white hole and what that might mean for future physics.

The new JMG Clips channel for sleep!

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Mar 9, 2024

What is the big rip, and can we stop it?

Posted by in categories: cosmology, nuclear energy, particle physics

If two points were ripped apart faster than light, they would no longer interact through any force of physics. Whereas a constant dark energy would leave behind already-intact objects, like clusters of galaxies, phantom energy could tear them apart. In a finite amount of time, billions of years from now, clusters would tear apart, followed by ever-smaller objects. Even atomic and nuclear bonds would not withstand the onslaught.

Eventually, space itself would dissolve in an event known as the Big Rip. Any two points, no matter how close, would be ripped infinitely far away from each other. The very structure of space-time, the causal foundations that make our universe work, would no longer behave. The universe would just break down.

However, luckily, most physicists do not believe this scenario can actually happen. For one, it’s unclear how this process of ripping interacts with the other laws of physics. For example, quarks cannot be torn apart — when you attempt to do so, you need so much energy that new quarks materialize out of the vacuum. So ripping apart quarks just might lead to other, interesting interactions.

Mar 3, 2024

Building a theory of quantum gravity

Posted by in categories: cosmology, mathematics, particle physics, quantum physics

The Isaac Newton Institute for Mathematical Sciences (INI) in Cambridge hosted a research programme on one of the most pressing problems in modern physics: to build a theory that can explain all the fundamental forces and particles of nature in one unifying mathematical framework. Such a theory of quantum gravity would combine two hugely successful frameworks on theoretical physics, which have so far eluded unification: quantum physics and Einstein’s theory of gravity.

The Black holes: bridges between number theory and holographic quantum information programme focusses on black holes, which play a hugely important part in this area, on something called the holographic principle, and on surprising connections to pure mathematics. This collection of articles explores the central concepts involved and gives you a gist of the cutting edge research covered by the INI programme.

Mar 3, 2024

Science 101: What are Dark Matter and Dark Energy?

Posted by in categories: computing, cosmology, particle physics, science

Argonne’s Science 101 series takes you back to the basics, with plain-language explanations of the scientific concepts behind our pivotal discoveries and our biggest innovations.

In this Science 101 video, postdoctoral researchers Gillian Beltz-Mohrmann and Florian Kéruzoré explore two of the biggest mysteries in science: dark matter and dark energy. These strange influences seem to be stretching the universe apart and clumping stuff together in unexpected ways. Together, they make up a whopping 95% of the universe, but because we can’t see or touch them, we don’t know what they are.

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