ALMA tagged posts

Supermassive black holes show selective feeding habits during galaxy mergers

Black holes are notorious for gobbling up everything that comes their way, but astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that even supermassive black holes can be picky eaters, and this can have a significant impact on their growth.

This discovery, now published in The Astrophysical Journal, was made by an international team of astronomers led by Makoto A. Johnstone, a Ph.D. candidate with the University of Virginia. The team used ALMA to study seven nearby galaxy mergers hosting supermassive black holes separated by only a few thousand light-years.

How galaxy mergers affect black holes
When two massive, gas-rich galaxies merge, gravity drives vast amounts of cold molecular gas toward the centers of both systems, where supermassive ...

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First-ever detection of ‘heavy water’ in a planet-forming disk

This artist’s impression shows the evolution of heavy water molecules (H2O, HDO, and D2O) as they have been observed in giant molecular clouds, a planet forming-disk, and comets—before they eventually may have made their way to Earth.
Credit: NSF/AUI/NSF NRAO/P. Vosteen, B. Saxton

The discovery of ancient water in a planet-forming disk reveals that some of the water found in comets—and maybe even Earth—is older than the disk’s star itself, offering breakthrough insights into the history of water in our solar system.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made a first-ever detection of doubly deuterated water (D₂O, or “heavy water”) in a planet-forming disk around V883 Ori, a young star...

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JWST may have found the Universe’s first stars powered by dark matter

New observations from the James Webb Space Telescope hint that the universe’s first stars might not have been ordinary fusion-powered suns, but enormous “supermassive dark stars” powered by dark matter annihilation. These colossal, luminous hydrogen-and-helium spheres may explain both the existence of unexpectedly bright early galaxies and the origin of the first supermassive black holes.

In the early universe, a few hundred million years after the Big Bang, the first stars emerged from vast, untouched clouds of hydrogen and helium. Recent observations from the James Webb Space Telescope (JWST) suggest that some of these early stars may have been unlike the familiar (nuclear fusion-powered) stars that astronomers have studied for centuries...

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Warped planet nurseries rewrite the rules of how worlds are born

Visualisation of the warped disc around the young star MWC 758, with warping exaggerated by a factor four to make it visible. Both panels show properties of the disc inferred from CO emission. On the left-hand side, we see deviations in the line-of-sight velocity from the expected rotation if the disc were flat. The variations in velocity can be used to infer the warp structure. On the right-hand side we see variations in the gas temperature, from which we can see evidence of shadowing in areas of the disc. Credit: A. Winter

New ALMA observations reveal that the discs where planets form are often slightly warped, challenging long-held assumptions and offering clues about the subtle misalignments seen in our own Solar System.

Astronomers using ALMA have discovered that planet-forming...

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