Latest news with #FermiBubbles
Yahoo
5 days ago
- Science
- Yahoo
Surprise Cosmic Clouds Likened to Finding Ice Cubes in a Volcano
Astronomers have found 11 unexpectedly cold hydrogen clouds hiding in the superheated turbulence of the Fermi Bubbles, in a discovery likened to finding ice cubes inside a volcano. The Fermi Bubbles are two lobes of incredibly energetic gas that extend 25,000 light-years above and below the Milky Way's disk, spanning a total height of 50,000 light-years. These still-mysterious structures were revealed in 2010 by the Fermi Gamma-Ray Space Telescope, which gave them their name. They originated from an outburst of galactic proportions, likely from the Milky Way's central black hole, and are moving at millions of miles per hour. Related: Now, using the unique capabilities of the US National Science Foundation Green Bank Telescope (NSF GBT), astronomers performed the deepest-ever radio survey of the Fermi Bubbles, twice as sensitive as previous surveys, and discovered 11 relatively cool, neutral hydrogen clouds embedded within these extreme environs. The Milky Way harbors many violent environments and the Fermi Bubbles are among the most intense. The plasma here reaches a temperature around 1 million Kelvin (999,730 degrees Celsius), so it's a surprise to spot hydrogen clouds that are at least 100 times cooler, or about 10,000 Kelvin. In fact, seeing such relatively frigid hydrogen clouds within the Fermi Bubbles is akin to "finding ice cubes in a volcano," explains Andrew Fox, astronomer at the Space Telescope Science Institute and study co-author. The discovery provides an existential galactic conundrum: "We didn't know that cold gas can survive in these extreme outflows. This challenges our understanding of how galaxies recycle and expel matter," says Rongmon Bordoloi, astrophysicist at North Carolina State University and the study's lead researcher. The hydrogen clouds vary in mass and size. The 8 that have been more clearly resolved are up to 1,470 solar masses and range between 13 and 91 light-years in length. They're also the highest latitude-hydrogen clouds yet discovered, about 13,000 light-years above the Milky Way's center. Given their structure and energetic surroundings, astronomers estimate that the hydrogen clouds may be several million years old. This matches an independent estimate of the age of the Fermi Bubbles themselves, challenging other formation models that suggest the bubbles could be as many as tens of millions of years in age. "It wouldn't be possible for the clouds to be present at all if the Fermi bubbles were 10 million years old or older," explains Bordoloi. Their extrapolated age suggests the hydrogen clouds were carried high into the Fermi Bubbles by the nuclear wind, or outflow from the Milky Way's nucleus. This wind, which blasts out at hundreds of kilometers per second, is responsible for cycling mass and energy throughout a galaxy, circulating it from the galactic center to the galactic halo. Jay Lockman, astronomer at the Green Bank Observatory and study co-author, clarifies the importance of the clouds in revealing the nuclear wind: "Just as you can't see the motion of the wind on Earth unless there are clouds to track it, we can't see the hot wind from the Milky Way but can detect radio emission from the cold clouds it carries along." As on Earth, these clouds are ephemeral, with a projected lifespan of up to 8 million years – a snap of the fingers on galactic timescales. In fact, they've already changed much, and may have been part of a larger cloud that was fragmented by the surrounding plasma. Conversely, the hydrogen clouds may have condensed from the surrounding plasma due to thermal instability. Overall, this study has universal implications. Finding such cool hydrogen clouds within the chaos of the Fermi Bubbles isn't just relevant to the Milky Way. It also helps improve models of galactic evolution, reshaping astronomers' understanding of how matter and energy are cycled throughout galaxies across the cosmos. This research is published in The Astrophysical Journal Letters. Related News Is 3I/ATLAS 'Comet' an Alien Probe? These Are The Signs to Look For. Early Forms of Cells Could Form in The Lakes of Saturn's Moon Titan Blinking 'Unicorn' Discovered in Space a One-of-a-Kind Object Solve the daily Crossword
Gizmodo
19-07-2025
- Science
- Gizmodo
‘Ice Cubes in a Volcano': Scientists Baffled by Mysterious Clouds in Center of the Milky Way
In the center of our galaxy, gigantic, balloon-like structures of high-energy radiation extend thousands of light-years above and below the Milky Way's plane. Known as the Fermi bubbles, the massive lobes may have been the result of a violent outburst in our galaxy's recent past. A new discovery of cold hydrogen clouds embedded inside the bubbles adds another level of mystery to the objects, suggesting they're only a few million years old—practically brand-new, by cosmic standards. Using the National Science Foundation's Green Bank Telescope in West Virginia, a team of scientists discovered something extremely odd. Lurking inside the hot Fermi bubbles are clouds of cold gas that shouldn't be there, forcing scientists to wonder how the cooler gas manages to survive in the superheated, extreme environment. The new findings, published in The Astrophysical Journal Letters, shed light on how galaxies evolve over time. The Fermi bubbles were discovered in 2010 by NASA's Fermi Gamma-ray Space Telescope. The two orbs form an hourglass structure, one stretching above and another below the center of the Milky Way. Each lobe is around 25,000 light-years tall, made up of gamma rays and high-energy cosmic rays. 'Fermi bubbles are a relatively recent discovery – they were first identified by telescopes that 'see' gamma rays in 2010 – there are different theories about how it happened, but we do know that it was an extremely sudden and violent event, like a volcanic eruption but on a massive scale,' Rongmon Bordoloi, associate professor of physics at North Carolina State University and co-author of the research, said in a statement. The team behind the study was observing the Fermi bubbles to gather high-resolution data about the composition of the hot gas within the structure. The majority of gas inside the Fermi bubbles is super-hot, measuring at around 1 million degrees Kelvin. Surprisingly, the team also found clouds of neutral hydrogen gas dotted within the bubbles around 12,000 light-years above the center of the galaxy and as massive as several thousand Suns. The gas in the clouds, however, is relatively cold compared to the rest of the gas in the bubbles. 'They're around 10,000 degrees Kelvin, so cooler than their surroundings by at least a factor of 100,' Andrew Fox, astronomer at the Space Telescope Science Institute and coauthor of the paper, said in a statement. 'Finding those clouds within the Fermi bubble is like finding ice cubes in a volcano.' Considering their extreme environment, the clouds of hydrogen should have been destroyed, a process that would take over a few million years. This means that the Fermi bubbles are much younger than expected. 'It wouldn't be possible for the clouds to be present at all if the Fermi bubbles were 10 million years old or older,' Bordoloi said. The scientists behind the study believe that the clouds were swept up from the center of the Milky Way and carried by the hot wind that formed the Fermi bubbles. Jay Lockman, an astronomer at the Green Bank Observatory and coauthor of the paper, compared the system to a more familiar phenomenon: 'Just as you can't see the motion of the wind on Earth unless there are clouds to track it, we can't see the hot wind from the Milky Way but can detect radio emission from the cold clouds it carries along.'
Yahoo
17-07-2025
- Science
- Yahoo
'Ice cube' clouds discovered at the galaxy's center shouldn't exist — and they hint at a recent black hole explosion
When you buy through links on our articles, Future and its syndication partners may earn a commission. Two of the strangest structures in the galaxy just got even stranger. Ballooning above and below the Milky Way's center like a massive hourglass, the mysterious Fermi bubbles loom large over our galaxy. These enormous twin orbs of superheated plasma have been gushing out of the galactic center for millions of years. Today, they span some 50,000 light-years from tip to tip, collectively making them half as tall as the Milky Way is long. Now, scientists studying the perplexing bubbles with the U.S. National Science Foundation Green Bank Telescope in West Virginia have discovered something shocking: Nestled deep within the superhot bubbles are gargantuan clouds of cold hydrogen gas that have inexplicably survived in an extreme environment. According to the researchers, these bewildering clouds are likely the remnants of much larger structures that puffed out of the galaxy's center several million years ago. "Think of it like dropping an ice cube into boiling water: a small one melts quickly, but a larger one lasts longer — even as it dissolves," lead study author Rongmon Bordoloi, an associate professor in the Department of Physics at North Carolina State University, told Live Science in an email. "We believe these clouds may be remnants of much larger structures that are currently being eroded by the galactic wind." The discovery could indicate that our galaxy's central black hole experienced a violent outburst of matter more recently than previously thought, Bordoloi added. The research describing the clouds was published July 7 in The Astrophysical Journal Letters. Baffling bubbles Towering over the galactic center, the Fermi bubbles were discovered in 2010 by NASA's Fermi Gamma-ray Space Telescope. Despite being comparable to our galaxy in size, the bubbles are visible only in gamma-rays, and they overlap with an equally mysterious X-ray counterpart known as the eROSITA bubbles. These bubbles are incredibly hot, with the plasma that makes up the Fermi bubbles reaching more than a million kelvins (nearly 2 million degrees Fahrenheit). It's thought that the bubbles are likely the result of an ancient, violent outburst from the Milky Way's central black hole, which spewed twin jets of matter above and below the galactic plane simultaneously, scooping up nearby matter in the process and flinging it outward into space. Related: Scientists discover rare planet at the edge of the Milky Way, using space-time phenomenon predicted by Einstein The newly discovered cold hydrogen clouds may be remnants of some of that matter, according to the study authors. Spotted with the Green Bank Telescope, the cold clouds range from about 13 to 91 light-years across, making each one many times larger than our solar system. However, for those cold clouds to survive in the superhot environment where they were discovered — well within the Fermi bubbles, about 13,000 light-years above the galaxy's center — they must have been significantly larger when they were first swept up into the thrall of the bubbles, Bordoloi said. RELATED STORIES —Behold, 'The Beast': Gigantic animal-like plasma plume 13 times wider than Earth hovers over the sun —Scientists detect most massive black hole merger ever — and it birthed a monster 225 times as massive as the sun —100 undiscovered galaxies may be orbiting the Milky Way, supercomputer simulations hint "In principle, these clouds shouldn't have survived this long," he added. "Yet they do exist, which gives us a kind of clock: their survival implies that the black hole at the Milky Way's center erupted just a few million years ago. In cosmic terms, that's a blink of an eye." This discovery could help solve a major mystery about the Fermi bubbles by significantly constraining how old they are. This age, in turn, hints that our galaxy's monster black hole may experience violent, sporadic outbursts whenever large amounts of material fall into it, with the last one occurring more recently than previously thought. However, the precise schedule of black hole eruptions in our galaxy remains an open question. "What's clear is that features like the Fermi Bubbles — and more recently, the eROSITA Bubbles — suggest the center of the Milky Way has been much more active in the recent past than we once believed," Bordoloi concluded. Solve the daily Crossword
