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Archive for the ‘cosmology’ category: Page 14

Feb 19, 2024

Gas on the run — ALMA spots the Shadow of a Molecular Outflow from a Quasar when the Universe was less than one billion years old

Posted by in category: cosmology

Theoretical predictions have been confirmed with the discovery of an outflow of molecular gas from a quasar when the Universe was less than a billion years old.

A quasar is a compact region powered by a supermassive black hole located in the center of a massive galaxy.

They are extremely luminous, with a point-like appearance similar to stars, and are extremely distant from Earth.

Feb 18, 2024

There may be a ‘dark mirror’ universe within ours where atoms failed to form, new study suggests

Posted by in categories: cosmology, particle physics

The invisible substance called dark matter remains one of the biggest mysteries in cosmology. Perhaps, a new study suggests, this strange substance arises from a ‘dark mirror universe’ that’s been linked to ours since the dawn of time.

Feb 17, 2024

A Study Suggests Black Holes Can Create Space Lasers—Just Like Einstein Thought

Posted by in categories: cosmology, physics

A new paper theorizes that in rare cases, gravitational waves could propagate across the universe like a laser.

Feb 17, 2024

Discovery of unexpected ultramassive galaxies may not rewrite cosmology, but still leaves questions

Posted by in category: cosmology

Ever since the James Webb Space Telescope (JWST) captured its first glimpse of the early universe, astronomers have been surprised by the presence of what appear to be more “ultramassive” galaxies than expected. Based on the most widely accepted cosmological model, they should not have been able to evolve until much later in the history of the universe, spurring claims that the model needs to be changed.

This would upend decades of established science.

“The development of objects in the universe is hierarchical. You start small and get bigger and bigger,” said Julian Muñoz, an assistant professor of astronomy at The University of Texas at Austin and co-author of a recent paper published in Physical Review Letters that tests changes to the cosmological model. The study concludes that revising the standard cosmological model is not necessary. However, astronomers may have to revisit what they understand about how the first formed and evolved.

Feb 17, 2024

Dark matter detected dangling from the cosmic web for 1st time

Posted by in category: cosmology

Last year, the Keck Cosmic Web Imager, also atop Maunakea, caught the first direct light emanating from wispy web filaments that cross one another and stretch across the darkest corners of space. These are filaments that sit isolated between galaxies, in the largest and most hidden portions of the cosmic web.

“Seeing” the location of dark matter around these cosmic web strands is a completely different story, however.

That’s because, despite making up an estimated 85% of all the matter in the universe, dark matter is invisible because it doesn’t interact with light like everyday matter that comprises stars and dust does.

Feb 17, 2024

Euclid Begins its 6-Year Survey of the Dark Universe

Posted by in categories: cosmology, mapping

ESA’s Euclid mission was launched in July 2023 and has already sent home test images showing that its instruments are ready to go. Now, the space telescope begins mapping huge swaths of the sky, focusing on an area for 70 minutes at a time. Throughout its 6-year mission, it will complete 40,000 of these ‘pointings’, eventually observing 1.5 billion galaxies in the sky. Astronomers will use this map to measure how dark matter and dark energy have changed over time.

Feb 17, 2024

Cosmic Super Bowl? The Milky Way’s black hole is shaping spacetime into a football

Posted by in category: cosmology

It would appear that Sagittarius A got into the spirit of the Super Bowl.

Feb 16, 2024

A star like a Matryoshka doll: New theory for gravastars

Posted by in categories: cosmology, information science, physics, singularity

The interior of black holes remains a conundrum for science. In 1916, German physicist Karl Schwarzschild outlined a solution to Albert Einstein’s equations of general relativity, in which the center of a black hole consists of a so-called singularity, a point at which space and time no longer exist. Here, the theory goes, all physical laws, including Einstein’s general theory of relativity, no longer apply; the principle of causality is suspended.

This constitutes a great nuisance for science—after all, it means that no information can escape from a black hole beyond the so-called event horizon. This could be a reason why Schwarzschild’s solution did not attract much attention outside the theoretical realm—that is, until the first candidate for a black hole was discovered in 1971, followed by the discovery of the black hole in the center of our Milky Way in the 2000s, and finally the first image of a black hole, captured by the Event Horizon Telescope Collaboration in 2019.

In 2001, Pawel Mazur and Emil Mottola proposed a different solution to Einstein’s field equations that led to objects that they called gravitational condensate stars, or gravastars. Contrary to black holes, gravastars have several advantages from a theoretical astrophysics perspective.

Feb 15, 2024

‘Beyond what’s possible’: New JWST observations unearth mysterious ancient galaxy

Posted by in category: cosmology

Our understanding of how galaxies form and the nature of dark matter could be completely upended after new observations of a stellar population bigger than the Milky Way from more than 11 billion years ago that should not exist.

A paper published today in Nature details findings using new data from the James Webb Space Telescope (JWST). The results find that a in the —observed 11.5 billion years ago (a cosmic redshift of 3.2)—has an extremely old population of stars formed much earlier—1.5 billion years earlier in time (a redshift of around 11). The observation upends current modeling, as not enough dark matter has built up in sufficient concentrations to seed their formation.

Swinburne University of Technology’s Distinguished Professor Karl Glazebrook led the study and the international team, who used the JWST for spectroscopic observations of this massive quiescent galaxy.

Feb 14, 2024

Most detailed X-ray sky map bolsters standard model of cosmology

Posted by in categories: cosmology, government

The picture was the result of the first six months of operation of eROSITA (Extended Roentgen Survey with an Imaging Telescope Array), one of two X-ray telescopes that were launched into space in July 2019 aboard the Russian spacecraft SRG (Spectrum-Roentgen-Gamma). eROSITA scans the sky as the spacecraft spins, and collects data over wider angles than are possible for most other X-ray observatories. This enables it to slowly sweep the entire sky every six months.

By an unusual arrangement, the eROSITA team is split into two — with a group based in Germany and one based in Russia — and each has exclusive access to eROSITA data from only half of the sky. The mission was originally intended to cover the sky eight times. But Russia’s full-scale invasion of Ukraine in 2022 led the German government to freeze its collaborations, and eROSITA was put on stand-by. By then, it had completed four full sky scans.

The data that Bulbul and her collaborators have used so far were from their half of the sky, collected during the first scan. Even so, the results are already among the most precise cosmological measurements ever made. It is unclear when the Russia-based group will publish its data and analysis.

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