Galaxies are gravitationally bound, large-scale astrophysical systems composed primarily of dark matter, stars, stellar remnants, gas, and dust, often embedded in extended dark matter halos. They exhibit diverse morphologies, including spiral, elliptical, and irregular types, and span mass scales from roughly 10⁷ to over 10¹² solar masses. Their internal dynamics are governed by gravity and angular momentum distribution, with baryonic components organized into disks, bulges, and halos, and frequently hosting central supermassive black holes. Galaxies are fundamental units of cosmic structure formation, participating in hierarchical assembly, mergers, and interactions within larger environments such as groups, clusters, and filaments of the cosmic web.
Galaxy clusters are the largest gravitationally bound structures in the universe, with each containing hundreds or even thousands of galaxies. When two of these giants collide, they send powerful shock waves through one another, ...
Astronomy
Nov 14, 2025
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The ESA's Euclid space telescope has been in space for just over a year, investigating some of the deepest mysteries of the cosmos. By observing cosmic structures up to a distance of 10 billion light-years, the observatory ...
Astronomy
Nov 13, 2025
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The discovery of a superheated star factory that forms stars 180 times faster than our own Milky Way could help solve a long-standing puzzle about how galaxies grew so quickly in the early universe.
Astronomy
Nov 12, 2025
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An international team of astronomers has employed the James Webb Space Telescope (JWST) to observe a distant galaxy designated SXDF-NB1006-2. As a result, they found that SXDF-NB1006-2 is a young starburst galaxy that experiences ...
At the heart of the Milky Way, just 27,000 light-years from Earth, there is a supermassive black hole with a mass of more than 4 million suns. Nearly all galaxies contain a supermassive black hole, and many of them are much ...
Astronomy
Nov 4, 2025
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For the first time, scientists have the calculations and simulations to explain mysterious flashes from the galaxy OJ 287. Roughly twice every 12 years, from 3.5 billion light years away, the light equivalent of 1 trillion ...
Astronomy
Oct 29, 2025
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So much happened in the earliest moments of the universe. Elementary particles appeared, the first nuclei of hydrogen and helium, and fluctuations of energy and matter set into motion the formation of galaxies and supermassive ...
Astronomy
Oct 28, 2025
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Small and unassuming, Segue 1 is a nearby dwarf galaxy containing only a handful of stars—too few to provide the gravity needed to keep itself from scattering into space. Like other dwarf galaxies, it was long believed that ...
Astronomy
Oct 27, 2025
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Scientists have released a new study on the arXiv preprint server that catalogs the universe by mapping huge clusters of galaxies.
Astronomy
Oct 22, 2025
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Astronomers using the James Webb Space Telescope (JWST) have captured the most detailed look yet at how galaxies formed just a few hundred million years after the Big Bang—and found they were far more chaotic and messy than ...
Astronomy
Oct 21, 2025
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