Latest news with #AtacamaLargeMillimeterWaveArray
Yahoo
02-04-2025
- Science
- Yahoo
This Deep-Space Spiral Galaxy Does Something It Shouldn't
Scientists are scratching their heads after taking a closer look at 2MASX J23453268−0449256, a spiral galaxy with a mouthful of a name. Nearly 1 billion light-years from Earth, the galaxy contains something it shouldn't: a supermassive black hole with jets so powerful, the spiral should no longer be stable. J2345-0449—as the galaxy is thankfully also known—was found in 2014, when astronomers in India hunted down a giant radio source known to possess relativistic jets, whose blasts of plasma travel at nearly the speed of light. Even then, the astronomers knew that J2345-0449 was strange: Relativistic jets are some of the universe's most powerful particle accelerators, and they're not typically found in spiral galaxies. Adding to the mystery was the size of J2345-0449's black hole, which the team considered "unusually massive" for a bulgeless disk galaxy. They were right to be surprised. More than a decade later, the same astronomers have completed an in-depth investigation of J2345-0449 using the Hubble Space Telescope, the Giant Metrewave Radio Telescope, and the Atacama Large Millimeter Wave Array. Published last week in Monthly Notices of the Royal Astronomical Society, their findings highlight the galaxy's bizarre combination of structural components, which appear to contradict each other despite likely having "peacefully co-evolved." J2345-0449's jets extend 6 million light-years away from its central supermassive black hole. Credit: Bagchi and Ray et al/Giant Metrewave Radio Telescope J2345-0449 might be three times the size of the Milky Way, but its central supermassive black hole is even more intimidating: The astronomers say its mass is billions of times larger than our Sun's. (Sagittarius A, the Milky Way's black hole, is merely 4 million times as massive as the Sun.) Though black holes don't produce their own radiation, they can influence their surroundings in ways that do. J2345-0449 exhibits signs of suppressed star formation in its central region; while the mechanisms of star formation suppression aren't well known, the astronomers think feedback from J2345-0449's black hole is pumping the brakes. Accretion disks are known to "reroute" material that would otherwise fall into a black hole. When that happens—or when an accretion disk squeezes infalling material—a plasma jet forms, spewing energy outward, away from the black hole. These blasts are believed to play a role in J2345-0449's suppression of star formation, which in turn could produce powerful radio jets. But jets of this capacity would render any other spiral galaxy unstable. Galaxies of this type—including our own Milky Way—are considered too fragile for the immense turbulence produced by such jets, which could disturb the disk's wispy structure. "This discovery is more than just an oddity—it forces us to rethink how galaxies evolve, and how supermassive black holes grow in them and shape their environments," lead study author Joydeep Bagchi told the Royal Astronomical Society.
Yahoo
21-03-2025
- Science
- Yahoo
A terrifying fate may lurk inside the Milky Way
All good things come to an end—even the Milky Way. Our home galaxy's demise isn't estimated to occur for at least another 4 or 5 billion years, when astronomers believe it will start colliding with its neighbor Andromeda. However, a new analysis of a more distant galaxy is hinting at another dramatic outcome. Instead of being annihilated from without, the Milky Way's cosmic destruction could begin from within. The spiral galaxy 2MASX J23453268−0449256 is located nearly 1 billion light-years away from Earth, and measures about three times the size of the Milky Way. Like our own galaxy, a supermassive black hole lurks at its center. But while our Sagittarius A (Sgr A*) currently exists in very cosmically quiet, dormant conditions (for a black hole), the one inside J23453268−0449256 spews chaotic, 6 million light-year-long jets of energy. That's what an international team has discovered using data collected by the Hubble Space Telescope, the Giant Metrewave Radio Telescope, the Atacama Large Millimeter Wave Array, and multi-wavelength analyses. According to their study published March 20 in the journal Monthly Notices of the Royal Astronomical Society, these findings are challenging conventional notions of how galaxies operate, and what forces they are capable of unleashing. Simply put, experts previously believed a galaxy like J23453268−0449256 couldn't survive under its own conditions. The roiling gamma, cosmic, and X-rays documented coming from its black hole are almost only seen in elliptical galaxies. Based on traditional theory, these powerful radio jets should be disrupting the spiral galaxy's comparatively delicate structure. However, that's not the case at all for J23453268−0449256. The galaxy appears pretty stable, with well-defined spiral arms, an untroubled stellar ring, and a bright nuclear bar. 'This discovery is more than just an oddity—it forces us to rethink how galaxies evolve, and how supermassive black holes grow in them and shape their environments,' Joydeep Bagchi, a study lead author and astronomy professor at India's CHRIST University, Bangalore, said in a statement. One difference appears to be its ability to form new stars. Although the galaxy is surrounded by a halo of X-ray-emitting gas needed to make them, the supermassive black hole's energy jets act like a deep space oven. This appears to prevent the halo from cooling enough to form new stars. Despite this stellar anomaly, J23453268−0449256 already hosts an untold number of stars. 'If a spiral galaxy can not only survive but thrive under such extreme conditions, what does this mean for the future of galaxies like our own Milky Way?' wondered Bagchi. This type of scenario could begin if the Milky Way's black hole Sgr A* ever begins devouring a star, gas cloud, or even a smaller dwarf galaxy. Previously documented in other galaxies, these Tidal Disruption Events (TDEs) are as dramatic as they are powerful. But depending on their direction, there are scenarios in which any future life on Earth wouldn't survive the experience. If a hypothetical Milky Way TDE's cosmic rays lined up with the solar system, the effects would cause almost incomprehensible devastation. The energy beams could strip planetary atmospheres, irradiate DNA enough to cause genetic mutations, as well as destroy the Earth's ozone and kick off dinosaur-level mass extinctions. While astronomers believe that the Milky Way hosted those kinds of radio jets in the past, the chance of it occurring any time in the near future is pretty slim. Regardless of the Milky Way's ultimate celestial fate, discovering and studying unique neighboring galaxies like J23453268−0449256 allows astronomers to learn more about our surprising, complex universe. 'Understanding these rare galaxies could provide vital clues about the unseen forces governing the universe—including the nature of dark matter, the long-term fate of galaxies, and the origin of life,' said study co-author and PhD candidate Shankar Ray. 'Ultimately, this study brings us one step closer to unraveling the mysteries of the cosmos, reminding us that the universe still holds surprises beyond our imagination.'
