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.
An international team of astronomers has discovered an instance of two galaxies aligned in a way where their gravity acts as a compound lens. The group has written a paper describing the findings and posted it on the arXiv ...
A story of survival is unfolding at the outer reaches of our galaxy, and NASA's Hubble Space Telescope is witnessing the saga.
Astronomy
Nov 14, 2024
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There is a region of the sky where astronomers fear to look. Filled with dark clouds of dust, it hides an unseen mass. A mass so large it is pulling the Milky Way and other galaxies toward it.
Astronomy
Nov 13, 2024
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Scientists using observations from NASA's Neil Gehrels Swift Observatory have discovered, for the first time, the signal from a pair of monster black holes disrupting a cloud of gas in the center of a galaxy.
Astronomy
Nov 13, 2024
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An international team led by the University of Geneva (UNIGE) has identified three ultra-massive galaxies—nearly as massive as the Milky Way—already in place within the first billion years after the Big Bang.
Astronomy
Nov 13, 2024
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The Hubble Classification, also known as the Hubble Sequence, is a widely recognized method for systematically categorizing galaxy morphology. Galaxies are classified into elliptical, lenticular, and spiral (or barred spiral) ...
Astronomy
Nov 7, 2024
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Supermassive black holes exist at the center of most galaxies, and modern telescopes continue to observe them at surprisingly early times in the universe's evolution.
Astronomy
Nov 4, 2024
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Stare deeply at these galaxies. They appear as if blood is pumping through the top of a flesh-free face. The long, ghastly "stare" of their searing eye-like cores shines out into the supreme cosmic darkness.
Astronomy
Oct 31, 2024
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Researchers at the University of Minnesota Twin Cities College of Science and Engineering have developed a new technique that reconstructs two dimensional (2D) radio images–visual representations created from radio waves–into ...
Astronomy
Oct 22, 2024
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Just like we use photos to reflect on memories of our past, astrophysicists want to use images of far-off galaxies to understand what the universe was like in its juvenile years. But current imaging technology can only reach ...
Astronomy
Oct 22, 2024
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