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Archive for the ‘cosmology’ category: Page 74

Feb 4, 2024

Lightest Black Hole or Heaviest Neutron Star? MeerKAT Uncovers a Mysterious Object in Milky Way

Posted by in category: cosmology

An international team of astronomers have found a new and unknown object in the Milky Way that is heavier than the heaviest neutron stars known and yet simultaneously lighter than the lightest black holes known.

Using the MeerKAT Radio Telescope, astronomers from a number of institutions including The University of Manchester and the Max Planck Institute for Radio Astronomy in Germany found an object in orbit around a rapidly spinning millisecond pulsar located around 40,000 light years away in a dense group of stars known as a globular cluster.

Using the clock-like ticks from the millisecond pulsar they showed that the massive object lies in the so-called black hole mass gap.

Feb 4, 2024

Scientists Find First Observed Evidence That Our Universe May Be a Hologram

Posted by in categories: cosmology, holograms, physics

Physicists finds evidence from just after the Big Bang that supports the controversial holographic universe theory.

Feb 3, 2024

In a ‘Dark Dimension,’ Physicists Search for Missing Matter

Posted by in categories: cosmology, quantum physics

An idea derived from string theory suggests that dark matter is hiding in a (relatively) large extra dimension. The theory makes testable predictions that physicists are investigating now.

Feb 3, 2024

Magnetic launch of black hole jets in Perseus A

Posted by in categories: cosmology, physics

The Event Horizon Telescope collaboration, including scientists from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has recently resolved the jet base of an evolving jet of plasma at ultra-high angular resolution.

The international team of scientists used the Earth-size telescope to probe the in the nucleus of the radio galaxy 3C 84 (Perseus A), one of the closest active supermassive in our cosmic neighborhood.

These novel results provide new insight into how jets are launched, revealing that in this cosmic tug of war, the magnetic fields overpower gravity. The study is published in the journal Astronomy & Astrophysics.

Feb 3, 2024

Ghost in the Cosmos: Almost Invisible Galaxy Challenges Dark Matter Model

Posted by in categories: cosmology, physics

A group of astrophysicists led by Mireia Montes, a researcher at the Instituto de Astrofísica de Canarias (IAC), has discovered the largest and most diffuse galaxy recorded until now. The study has been published in the journal Astronomy & Astrophysics, and has used data taken with the Gran Telescopio Canarias (GTC) and the Green Bank Radiotelescope (GBT).

Nube is an almost invisible dwarf galaxy discovered by an international research team led by the Instituto de Astrofísica de Canarias (IAC) in collaboration with the University of La Laguna (ULL) and other institutions.

The name was suggested by the 5-year-old daughter of one of the researchers in the group, and is due to the diffuse appearance of the object. Its surface brightness is so faint that it had passed unnoticed in the various previous surveys of this part of the sky, as if it were some kind of ghost. This is because its stars are so spread out in such a large volume that “Nube” (the Spanish for “Cloud”) was almost undetectable.

Feb 2, 2024

Team of astronomers discovers galaxy that shouldn’t exist

Posted by in category: cosmology

A team of astronomers, led by Arizona State University Assistant Research Scientist Tim Carleton, has discovered a dwarf galaxy that appeared in James Webb Space Telescope imaging that wasn’t the primary observation target.

Galaxies are bound together by gravity and made up of stars and planets, with vast clouds of dust and gas as well as dark matter. Dwarf galaxies are the most abundant galaxies in the universe, and are by definition small with low luminosity. They have fewer than 100 million stars, while the Milky Way, for example, has nearly 200 billion stars.

Recent observations of the abundance of “ultra-diffuse galaxies” beyond the reach of previous large spectroscopic surveys suggest that our understanding of the dwarf galaxy population may be incomplete.

Feb 2, 2024

To infinity and beyond

Posted by in categories: cosmology, quantum physics

A physicist’s wild romp through the multiverse probes space-time, string theory, and everything in between.

Melanie Frappier melanie.frappier@ukings.ca Authors Info & Affiliations

Science.

Feb 2, 2024

Astronomers Make Historic Discovery: Oldest Black Hole Ever Observed Detected

Posted by in category: cosmology

The young host galaxy, called GN-z11, glows from such an energetic black hole at its centre. Black holes cannot be directly observed, but instead they are detected by the tell-tale glow of a swirling accretion disc, which forms near the edges of a black hole. The gas in the accretion disc becomes extremely hot and starts to glow and radiate energy in the ultraviolet range. This strong glow is how astronomers are able to detect black holes.

GN-z11 is a compact galaxy, about one hundred times smaller than the Milky Way, but the black hole is likely harming its development. When black holes consume too much gas, it pushes the gas away like an ultra-fast wind. This ‘wind’ could stop the process of star formation, slowly killing the galaxy, but it will also kill the black hole itself, as it would also cut off the black hole’s source of ‘food’

Maiolino says that the gigantic leap forward provided by JWST makes this the most exciting time in his career. “It’s a new era: the giant leap in sensitivity, especially in the infrared, is like upgrading from Galileo’s telescope to a modern telescope overnight,” he said. “Before Webb came online, I thought maybe the universe isn’t so interesting when you go beyond what we could see with the Hubble Space Telescope. But that hasn’t been the case at all: the universe has been quite generous in what it’s showing us, and this is just the beginning.”

Feb 1, 2024

The Troubling Mysteries at the Heart of Nuclear Bombs

Posted by in categories: cosmology, military

Plutonium-pit secrets, growing up in parallel universes, the strange aftermath of a fictional wildfire, and more books out now.

Jan 31, 2024

Bright galaxies put dark matter to the test

Posted by in categories: cosmology, physics

For the past year and a half, the James Webb Space Telescope has delivered astonishing images of distant galaxies formed not long after the Big Bang, giving scientists their first glimpses of the infant universe. Now, a group of astrophysicists has upped the ante: Find the tiniest, brightest galaxies near the beginning of time itself, or scientists will have to totally rethink their theories about dark matter.

The team, led by UCLA astrophysicists, ran simulations that track the formation of small galaxies after the Big Bang and included, for the first time, previously neglected interactions between gas and dark matter. They found that the galaxies created are very tiny, much brighter, and form more quickly than they do in typical simulations that don’‘t take these interactions into account, instead revealing much fainter galaxies.

Small galaxies, also called , are present throughout the universe, and are often thought to represent the earliest type of galaxy. Small galaxies are thus especially interesting to scientists studying the origins of the universe. But the small galaxies they find don’t always match what they think they should find. Those closest to the Milky Way spin quicker or are not as dense as in simulations, indicating that the models might have omitted something, such as these gas-dark matter interactions.

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