Category Astronomy/Space

New Evidence for the Nature of Matter from Ancient Galaxies in the Early Universe

New evidence for the nature of matter from ancient galaxies in the early universe
Distribution of primordial matter in cosmological models with hot dark matter (WDM, left) and cold dark matter. Credit: CDM, destra

Astrophysicists in Italy have shed new light on the nature of matter from the James Webb Space Telescope (JWST) detection of galaxies from 13 billion years ago and novel state-of-the-art numerical simulations of the first galaxies. The study adds another piece to the puzzle of the nature of matter in the universe.

While the commonly accepted paradigm of structure formation is based on non-relativistic matter that interacts only gravitationally, that is “cold” dark matter, alternative possibilities advocated to solve small-scale problems of the standard scenario rely on the hypothesis that dark matter is made of warm particles that possess a small, non-n...

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A New Measurement could Change our Understanding of the Universe

The cosmic distance ladder. © NASA, ESA, A.Feild (STScI), and A.Riess (STScI/JHU)

When it comes to measuring how fast the Universe is expanding, the result depends on which side of the Universe you start from. A recent study has calibrated the best cosmic yardsticks to unprecedented accuracy, shedding new light on what’s known as the Hubble tension.

The Universe is expanding — but how fast exactly? The answer appears to depend on whether you estimate the cosmic expansion rate — referred to as the Hubble’s constant, or H0 — based on the echo of the Big Bang (the cosmic microwave background, or CMB) or you measure H0 directly based on today’s stars and galaxies. This problem, known as the Hubble tension, has puzzled astrophysicists and cosmologists around the world.

A study carrie...

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‘Taffy Galaxies’ Collide, leave behind Bridge of Star-Forming Material

The Gemini North telescope, one half of the International Gemini Observatory, operated by NSF’s NOIRLab, captured this dazzling image of UGC 12914 and UGC 12915, which are nicknamed the Taffy Galaxies. Their twisted shape is the result of a head-on collision that occurred about 25 million years prior to their appearance in this image. A bridge of highly turbulent gas devoid of significant star formation spans the gap between the two galaxies.

Gemini North captures sprawling aftermath of head-on colllision between a pair of galaxies. The Gemini North telescope, one half of the International Gemini Observatory, operated by NSF’s NOIRLab, captured a dazzling image of UGC12914 and UGC312915, which are nicknamed the Taffy Galaxies...

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Astronomers witness the Birth of a very Distant Cluster of Galaxies from the Early Universe

This image shows several galaxies distributed over a black background. The galaxies have colours that range from blue, orange-red, yellow and white. In the centre of the image is a larger concentration of galaxies. Overlaid on the galaxies in the middle is a blue and semi-transparent region. It has a clumpy form with indistinct contours. There are smaller, dark blue regions around it.
Using the Atacama Large Millimeter/submillimeter Array (ALMA), of which ESO is a partner, astronomers have discovered a large reservoir of hot gas in the still-forming galaxy cluster around the Spiderweb galaxy — the most distant detection of such hot gas yet. Galaxy clusters are some of the largest objects known in the Universe and this result, published today in Nature, further reveals just how early these structures begin to form.

Astronomers have discovered a large reservoir of hot gas in the still-forming galaxy cluster around the Spiderweb galaxy — the most distant detection of such hot gas yet. Galaxy clusters are some of the largest objects known in the Universe and this result further reveals just how early these structures begin to form.

Using the Atacama Large Millimete...

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