Latest news with #LorenaHernández-García
Yahoo
16-04-2025
- Science
- Yahoo
Long-dormant black hole 'woke up' before our eyes — now, it's doing something that astronomers can't explain
When you buy through links on our articles, Future and its syndication partners may earn a commission. In December 2019, an ordinary galaxy 300 million light-years from us in the constellation Virgo suddenly woke up. After decades of inactivity, the black hole at the galaxy's heart burst with light. Now, the cosmic monster appears to be doing something that is forcing astronomers to re-evaluate their understanding of these massive celestial bodies. The black hole now gives off powerful X-rays at nearly regular intervals. These outbursts are known as quasi-periodic eruptions (QPEs), and have been observed emitting from other black holes. But the bursts observed here are up to 100 times more powerful than normal, according to new research. First observed in February 2024 by astronomers at Valparaiso University in Chile, this behavior grants scientists an unprecedented view of a black hole that seems to be awakening from dormancy with no sign of going back to sleep. Led by the Valparaiso team, a group of researchers published their observations of the black hole's QPE in a study on April 11 in the journal Nature Astronomy. In addition to giving astronomers a novel view of black holes, these events are also spurring researchers to reconsider how black holes behave. "This is the first time we have observed such an event in a black hole that seems to be waking up," the paper's first author Lorena Hernández-García, an astronomy researcher at Valparaiso University, said in a statement. "This rare event provides an opportunity for astronomers to observe a black hole's behaviour in real time." Related: Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it The galaxy, called SDSS1335+0728, first called attention to itself in 2019 when it unexpectedly started gleaming. At that time, astronomers from the European Southern Observatory studied the event by consulting NASA's Swift X-ray space telescope and data from the eROSITA X-ray telescope. After investigating the galaxy's central region — nicknamed Ansky — they concluded that the flash resulted from Ansky's massive black hole beginning an active phase. But in February 2024, Hernández-García's team noticed bursts of previously undetected X-rays emanating from Ansky, caught by X-ray space telescopes XMM-Newton and NASA's NICER, Chandra, and Swift. These QPEs are momentary, recurring X-ray flares. Astronomers believe QPEs result from interaction between accretion disks — the swirling ring of red-hot matter that surrounds a black hole — and nearby objects, like a star or a smaller black hole. But Ansky's QPEs aren't typical. They're remarkable because they last 10 times longer and are 10 times more luminous than average QPEs, the researchers said. Persisting for more than four days, they each release one hundred times more energy than what's expected. These QPEs reveal a whole new aspect of black holes that don't fit neatly into astronomers' prior understanding of the cosmic bodies. In particular, these unusual QPEs can help broaden our understanding of how these events occur. For example, there's no evidence that Ansky has shredded a star into its accretion disk, which is what researchers currently believe triggers most QPEs. Therefore, there must be another explanation for the impetus that causes the QPEs in this case. The X-ray bursts may instead come from energetic shocks in the accretion disk spurred by a small celestial object repeatedly disrupting its orbiting material, according to the paper. RELATED STORIES —Incredible photo shows supermassive black hole blowing a jet of matter into interstellar space —Black holes can destroy planets — but they can also lead us to thriving alien worlds. Here's how. —Black holes may obey the laws of physics after all, new theory suggests It's also possible that these repeated QPEs come from gravitational waves. The European Space Agency's upcoming Laser Interferometer Space Antenna (LISA), set to launch in 2035, may confirm that connection by detecting gravitational waves with greater fidelity than ever before. For now, Ansky is reshaping how we conceive of black holes. "Studying Ansky will help us to better understand black holes and how they evolve," Hernández-García said.
Yahoo
11-04-2025
- Science
- Yahoo
Awakening Black Hole's Wild Behavior Has Astronomers Stumped
A supermassive black hole 300 million light-years away has astrophysicists stumped. It lurks at the center of a galaxy called SDSS1335+0728, and, since 2019, researchers have been watching in real-time as it awoke from a quiescent slumber and started blazing with activity, belching out a series of eruptions of light. This in itself is consistent with how we know supermassive black holes to behave. But the behavior of this particular black hole – nicknamed Ansky – is so weird and wild that it's challenging to explain. "The bursts of X-rays from Ansky are 10 times longer and 10 times more luminous than what we see from a typical quasi-periodic eruption," says astrophysicist Joheen Chakraborty of MIT. "Each of these eruptions is releasing a hundred times more energy than we have seen elsewhere. Ansky's eruptions also show the longest cadence ever observed, of about 4.5 days. This pushes our models to their limits and challenges our existing ideas about how these X-ray flashes are being generated." The popular perception of a black hole is that of a cosmic vacuum cleaner, sitting in space constantly slurping up everything around it. This is only part of the rich and complex existence of the densest known objects in the Universe. Like anything with mass, their gravitational reach only extends so far; supermassive black holes can go through periods of raging activity, and periods of relative quiet, during which they just sort of sit there not really accreting much material at all. The supermassive black hole at the center of the Milky Way, for instance, is relatively quiescent. Astronomers believe that supermassive black hole activity, in which they devour huge amounts of material from the space around them, is critical to the evolution of the black holes and the galaxies that surround them. For one, the black holes have to have grown to their tremendous sizes somehow; and active supermassive black holes throughout the Universe suggest that active accretion is part of the growth process. In addition, most galaxies have a supermassive black hole in their centers. The activity of that black hole plays a role in its galaxy's star formation and chemical evolution. We know that supermassive black holes can be active or quiescent, and that they can transition between the two states, sputtering to life in a series of quasi-periodic eruptions. In 2019, Ansky became the first supermassive black hole observed switching to an active state in real-time. "This is the first time we have observed such an event in a black hole that seems to be waking up," says astronomer Lorena Hernández-García of the Millennium Institute of Astrophysics (MAS) and the University of Valparaíso in Chile, who led the research. "The first quasi-periodic eruption episode was discovered in 2019, and since then we've only detected a handful more. We don't yet understand what causes them. Studying Ansky will help us to better understand black holes and how they evolve." A black hole itself emits no detectable light. Activity in the extreme gravitational environment around a black hole is another matter. The friction and gravity at play in the material swirling around a supermassive black hole produce extreme temperatures that blaze with light as a black hole feeds. Scientists had thought that quasi-periodic eruptions kick off when an object such as a star or small black hole wanders a bit too close to a supermassive black hole and gets tangled up in the material swirling around it, causing repeated flares. The light detected emanating from Ansky, however, is not easy to explain. It's extremely bright across a range of wavelengths, from infrared to X-rays, and the eruptions last longer than predicted for a cosmic interloper. This is tremendously exciting… but it does mean that we're going to need a lot more data. "We thought that quasi-periodic eruptions were the result of small celestial objects being captured by much larger ones and spiraling down towards them. Ansky's eruptions seem to be telling us a different story. These repetitive bursts are also likely associated with gravitational waves that ESA's future mission LISA might be able to catch," says astronomer Erwan Quintin of the European Space Agency. "It's crucial to have these X-ray observations that will complement the gravitational wave data and help us solve the puzzling behavior of massive black holes." The research has been published in Nature Astronomy. We Were Wrong About Uranus: New Study Solves Long-Standing Mysteries Infrared AI Camera Proposed to Scan Earth's Skies For Signs of Alien Visitors 'City Killer' Asteroid's Origin Traced to an Unexpected Part of The Solar System
