Latest news with #ImadPasha
Yahoo
08-02-2025
- Science
- Yahoo
'Bullseye' Galaxy Captured in Spellbinding Hubble Image
Tens of millions of years ago, a humble blue dwarf galaxy plunged through space, leaving hoops of gas and dust in its wake. Now those hoops surround a "new" galaxy. Thanks to the Hubble Space Telescope, researchers at Yale University have discovered the freshly-named "bullseye galaxy," which features nine sparkling rings and more than doubles the size of our Milky Way. The bullseye galaxy's official name is LEDA 1313424, and it's an eye-watering 567 million light-years away from Earth. Yale astronomer Imad Pasha was reviewing ground-based imaging data from the DESI Legacy Survey when he spotted "a galaxy with several clear rings," which he "had to stop to investigate." Using Hubble's trusty ACS (Advanced Camera for Surveys) system, he and his colleagues pursued the above image of LEDA 1313424, which fully revealed the galaxy's bullseye shape. Hubble's image allowed Pasha to inspect eight of the bullseye's rings—more starry hoops than have been detected by any telescope in any galaxy, according to NASA. But faint patches of emission 70 kiloparsecs (228,309 light-years) away from the galaxy's center led the team to believe another ring swirled just out of sight. They used the Keck Cosmic Web Imager (KCWI) at Hawaii's W. M. Keck Observatory to capture the galaxy's spectroscopic data, and sure enough, a ninth ring lurked at the bullseye's outer edge. Artist's concept showing the distribution of LEDA 1313424's rings. Credit: NASA, ESA, Ralf Crawford (STScI) These rings formed in much the same way as ripples in a pond. When you drop a pebble into a body of water, small, ring-shaped waves ripple outward, gradually becoming larger and more spaced out. Pasha and his colleagues were delighted to find that, mathematically, the bullseye galaxy's rings follow the same pattern. When a blue dwarf galaxy passed through what's now the bullseye's center 50 million years ago, it triggered ripples of stellar material. While the two oldest rings spread outward and grew further apart, the newest rings continued to hug the galaxy's center more closely. That blue dwarf galaxy is still in the bullseye's vicinity—in fact, it's attached to the bullseye by a thin thread of gas roughly 130,000 light-years long. In the image at the top of this page, you can see it to the bullseye galaxy's immediate left. "We're catching the Bullseye at a very special moment in time," Pieter van Dokkum, astrophysicist and study co-author, told NASA. "There's a very narrow window after the impact when a galaxy like this would have so many rings."
Yahoo
06-02-2025
- Science
- Yahoo
Hubble Reveals Cosmic Bullet That Gave The Bullseye Galaxy Its Record-Breaking Rings
Just like fingerprints and snowflakes, no two galaxies in the entire Universe are exactly alike. But a new discovery 567 million light-years away really is jaw-droppingly unique. There, astronomers have found a galaxy girdled by, not one, but nine concentric rings – the aftermath of a violent encounter with a blue dwarf galaxy that shot right through its heart, sending shockwaves rippling out into space. Officially named LEDA 1313424, this galaxy has been given the appropriate title of the Bullseye Galaxy, and its serendipitous discovery is a new window into galaxy-on-galaxy crime. "We're catching the Bullseye at a very special moment in time," says astronomer Pieter van Dokkum of Yale University. "There's a very narrow window after the impact when a galaxy like this would have so many rings." So-called ring galaxies are extremely rare in the Universe, and they are thought to be the result of a very specific set of circumstances. Although space is mostly empty, galaxies are drawn together along filaments of the cosmic web, resulting in more collisions between them than you might expect. Interactions between galaxies can take many forms, and produce varied results. Ring galaxies – such as the mysterious and famous Hoag's Object – are thought to be the result of a collision in which one galaxy blasts straight through the center of another. The Bullseye Galaxy has confirmed that this process does indeed take place. Not far from the larger galaxy is a smaller one, seen in visible light images using the Hubble Space Telescope. Observations taken using the Keck Cosmic Web Imager (KCWI), which is optimized for visible blue wavelengths, revealed that this smaller galaxy is not only close to Bullseye, at a distance of just 130,000 kilometers (about 80,000 miles), but linked. "KCWI provided the critical view of this companion galaxy that we see in projection near the bullseye," says astronomer Imad Pasha of Yale University. "We found a clear signature of gas extending between the two systems, which allowed us to confirm that this galaxy is in fact the one that flew through the center and produced these rings." "The data from KCWI that identified the 'dart' or impactor is unique. There hasn't been any other case where you can so clearly see the gas streaming from one galaxy to the other, " van Dokkum adds. "That there is all this gas right between the velocity of one galaxy and the other is the key insight, showing that material is being pulled out of one galaxy, left behind by the other, or both. It physically fills up the entire space. The KCWI data enables us to see the tendril of gas that is still connecting these two galaxies." The rings are regions of higher density, where the galactic material has been pushed together by the rippling shocks. The clumping of the dust and gas triggers star formation, resulting in higher star density, which is why the rings glitter so brightly. The most distant ring is relatively faint and tenuous, and was only spotted in the KCWI images, at quite a distance from the main body of the galaxy. The entire galaxy is 250,000 light-years across. That gap between the rings is a marvel, showing that the rings propagate outwards in almost exactly the same way as predicted by theory, with the first two rings spreading quickly, with the subsequent rings forming later. It's like dropping a pebble in a pond. "If we were to look down at the galaxy directly, the rings would look circular, with rings bunched up at the center and gradually becoming more spaced out the farther out they are," Pasha says. The data provided by this marvelous galaxy will help astronomers adjust their models and theories, to better understand how such collisions play out. The researchers also hope future observations with upcoming telescopes will ferret out even more ring galaxies, lurking out there in the wide expanses of the cosmos. The research has been published in The Astrophysical Journal Letters. 10 Minutes of Violence Gave The Moon Its Very Own 'Grand Canyons' Astrophysicist Reveals The Key Facts About The Asteroid That May Hit Earth AI Can Predict Incredible Solar Storms Before They Strike
