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Archive for the ‘cosmology’ category: Page 60

Mar 27, 2024

New analysis reveals a tiny black hole repeatedly punching through a larger black hole’s disk of gas

Posted by in category: cosmology

At the heart of a far-off galaxy, a supermassive black hole appears to have had a case of the hiccups. Astronomers from MIT, Italy, the Czech Republic, and elsewhere have found that a previously quiet black hole, which sits at the center of a galaxy about 800 million light years away, has suddenly erupted, giving off plumes of gas every 8.5 days before settling back to its normal, quiet state.

Mar 27, 2024

Insights into Black Hole Feeding: Polarized Light Studies of Sgr A*

Posted by in category: cosmology

“Along with Sgr A* having a strikingly similar polarization structure to that seen in the much larger and more powerful M87* black hole, we’ve learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them,” said Dr. Sara Issaoun.


A recent study published in The Astrophysical Journal Letters discusses the most recent image of the supermassive black hole, Sagittarius A* (Sgr A, which is located approximately 27,000 light-years from Earth at the center of the Milky Way Galaxy. These new images that were obtained by Event Horizon Telescope (EHT) Collaboration are the first to identify the magnetic field lines of Sgr A* and comes after EHT first obtained images of Sgr A* in 2022. This study, which consists of more than 150 co-authors, holds the potential to help astronomers better understand the compositions of supermassive black holes throughout the universe.

For the study, the collaborative team of researchers used EHT to measure polarized light emitted by Sgr A*, which not only revealed the magnetic field lines for the first time, but also gained valuable insight into the properties and behavior of the magnetic field, as well. This study comes after astronomers previously identified the supergiant elliptical galaxy, M87*, was emitting powerful jets at nearly the speed of light after astronomers had discovered it also had large magnetic field lines. Therefore, researchers hope this recent study could produce the same long-term result.

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Mar 26, 2024

Sleeping supermassive black holes awakened briefly by shredded stars

Posted by in category: cosmology

A new investigation into an obscure class of galaxies known as Compact Symmetric Objects, or CSOs, has revealed that these objects are not entirely what they seem. CSOs are active galaxies that host supermassive black holes at their cores. Out of these monstrous black holes spring two jets traveling in opposite directions at nearly the speed of light. But in comparison to other galaxies that boast fierce jets, these jets do not extend out to great distances—they are much more compact.

For many decades, astronomers suspected that CSOs were simply young and that their jets would eventually travel out to greater distances. Now, reporting in three different papers in The Astrophysical Journal, a Caltech-led team of researchers has concluded that CSOs are not young but rather lead relatively short lives.

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Mar 26, 2024

How did the Big Bang get its name? Here’s the real story

Posted by in category: cosmology

Astronomer Fred Hoyle supposedly coined the catchy term to ridicule the theory of the Universe’s origins — 75 years on, it’s time to set the record straight.

Mar 25, 2024

More precise Understanding of Dark Energy achieved using AI

Posted by in categories: cosmology, robotics/AI

A UCL-led research team has used artificial intelligence (AI) techniques to infer the influence and properties of dark energy more precisely from a map of dark and visible matter in the universe covering the last 7 billion years.

The study, submitted to the Monthly Notices of the Royal Astronomical Society and available on the arXiv preprint server, was carried out by the Dark Energy Survey collaboration. The researchers doubled the precision at which key characteristics of the universe, including the overall density of dark energy, could be inferred from the map.

This increased precision allows researchers to rule out models of the universe that might previously have been conceivable.

Mar 25, 2024

Astronomers find evidence that blue supergiant stars can be formed by the merger of two stars

Posted by in category: cosmology

An international piece of research, led by the Instituto de Astrofísica de Canarias (IAC) has found clues to the nature of some of the brightest and hottest stars in our universe, called blue supergiants. Although these stars are commonly observed, their origin has been an old puzzle that has been debated for several decades.

Mar 24, 2024

If Our Part of the Universe is Less Dense, Would That Explain the Hubble Tension?

Posted by in categories: cosmology, physics

In the 1920s, Edwin Hubble and Georges Lemaitre made a startling discovery that forever changed our perception of the Universe. Upon observing galaxies beyond the Milky Way and measuring their spectra, they determined that the Universe was expanding. By the 1990s, with the help of the Hubble Space Telescope, scientists took the deepest images of the Universe to date and made another startling discovery: the rate of expansion is speeding up! This parameter, denoted by Lambda, is integral to the accepted model of cosmology, known as the Lambda Cold Dark Matter (LCDM) model.

Since then, attempts to measure distances have produced a discrepancy known as the “Hubble Tension.” While it was hoped that the James Webb Space Telescope (JWST) would resolve this “crisis in cosmology,” its observations have only deepened the mystery. This has led to several proposed resolutions, including the idea that there was an “Early Dark Energy” shortly after the Big Bang. In a recent paper, an international team of astrophysicists proposed a new solution based on an alternate theory of gravity that states that our galaxy is in the center of an “under-density.”

Continue reading “If Our Part of the Universe is Less Dense, Would That Explain the Hubble Tension?” »

Mar 24, 2024

Finding New Physics in Debris from Colliding Neutron Stars

Posted by in categories: cosmology, particle physics

Neutron star mergers are a treasure trove for new physics signals, with implications for determining the true nature of dark matter, according to research from Washington University in St. Louis.

On Aug. 17, 2017, the Laser Interferometer Gravitational-wave Observatory (LIGO), in the United States, and Virgo, a detector in Italy, detected gravitational waves from the collision of two neutron stars. For the first time, this astronomical event was not only heard in gravitational waves but also seen in light by dozens of telescopes on the ground and in space.

Physicist Bhupal Dev in Arts & Sciences used observations from this neutron star merger — an event identified in astronomical circles as GW170817 — to derive new constraints on axion-like particles. These hypothetical particles have not been directly observed, but they appear in many extensions of the standard model of physics.

Mar 24, 2024

Quantum Tornado Unlocks Mysteries of Black Holes

Posted by in categories: climatology, cosmology, quantum physics

A team of scientists has successfully mimicked black hole conditions by creating a quantum vortex in superfluid helium, shedding light on gravitational interactions and quantum field theories in curved spacetimes.

Scientists have for the first time created a giant quantum vortex to mimic a black hole in superfluid helium that has allowed them to see in greater detail how analog black holes behave and interact with their surroundings.

Research led by the University of Nottingham, in collaboration with King’s College London and Newcastle University, has created a novel experimental platform: a quantum tornado. They have created a giant swirling vortex within superfluid helium that is chilled to the lowest possible temperatures. Through the observation of minute wave dynamics on the superfluid’s surface, the research team has shown that these quantum tornados mimic gravitational conditions near rotating black holes. The research has been published today in Nature.

Mar 23, 2024

Speck of light glimpsed by Hubble is truly an enormous old galaxy, James Webb Space Telescope reveals

Posted by in category: cosmology

When it comes to the cosmic conundrum of how early galaxies grew to become so massive so quickly Gz9p3 could be a real puzzle. Not only is it more massive than expected, but it is around 10 times more massive than other galaxies the JWST has seen in similar eras of the universe’s history.

Related: James Webb Space Telescope complicates expanding universe paradox by checking Hubble’s work

“Just a couple of years ago, Gz9p3 appeared as a single point of light through the Hubble Space Telescope,” Kit Boyett, team member and a scientist at the University of Melbourne, wrote for the institute’s Pursuit publication. “But by using the JWST we could observe this object as it was 510 million years after the Big Bang, around 13 billion years ago.”

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