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.
For decades, astronomers have cast galaxy mergers as the universe's ultimate relationship drama: two galaxies collide, chaos erupts, black holes awaken and star formation comes to a screeching halt. Upending this long-held ...
Astronomy
Jul 21, 2026
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Stars and galaxies make up much of the universe's ordinary, observable matter. But for decades, scientists have wrestled with a cosmic conflict: There should be much more.
Astronomy
Jul 21, 2026
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Peak star formation took place during cosmic noon, between 2–3 billion years after the Big Bang. The star formation rate (SFR) back then was up to 100 times greater than it is today. For the SFR to be so high, gas had to ...
Astronomy
Jul 15, 2026
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Astronomers at Durham University have made a major advance in understanding how galaxies formed and evolved in the early universe. Using powerful new observations, the team discovered the most distant example ever found of ...
Astronomy
Jul 14, 2026
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Astronomers are closer to solving the mystery of how supermassive black holes feed themselves thanks to new images from the James Webb Space Telescope, or JWST. The images provide the clearest view ever seen of gaseous filaments ...
Astronomy
Jul 14, 2026
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Since gravitational waves were first detected in 2015, instruments including LIGO, Virgo and KAGRA have picked up a steady stream of signals from colliding black holes, building a catalog that now numbers in the hundreds. ...
Researchers working with data from the South Pole Telescope have released a major catalog of galaxy clusters, giving scientists a powerful new tool for studying how the universe grew and changed over billions of years. The ...
Astronomy
Jul 7, 2026
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Astronomers using computer simulations have investigated whether a class of star clusters nicknamed "cosmic wallflowers" could be the long-sought ancestors of the globular clusters we see orbiting galaxies today. Their paper, ...
The European Space Agency's Euclid space telescope has discovered 31 of the most ancient quasars ever found. Two of these giant and dazzling galaxy cores, powered by gargantuan black holes, are the earliest quasars yet observed ...
Astronomy
Jul 6, 2026
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An international team of astronomers reports the discovery of a new massive barred spiral galaxy. The newfound galaxy, designated M1149-BSG-z5, was identified using the James Webb Space Telescope (JWST). The finding was detailed ...
