NASA’s Chandra X-ray Observatory has discovered a supermassive black hole that has ripped apart a star and is now using the leftover materials to hit another star or a smaller black hole. This finding helps explain two mysteries in space and gives us insights into the areas around large black holes.
As seen in an illustration, a disk of material (in red, orange, and yellow) was generated after the black hole destroyed the star. This disk grew over the years and eventually collided with another object, either a star or a small black hole, which orbits the black hole. Each time they crash, they produce X-rays, detectable by Chandra telescope.
In 2019, a telescope in California spotted a bright flash of light. This event was “tidal disruption event” (TDE), in which a black hole pulls apart a star that gets too close. They named this event AT2019qiz.
Researchers have also observed a cosmic event called “quasi-periodic eruptions” (QPEs), short bursts of X-rays near supermassive black holes.
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Recent research suggests that Tidal Disruption Events (TDEs) and QPEs are likely related. Researchers think that QPEs happen when an object crashes into the disk of leftover material after a black hole has torn apart a star. While there could be other reasons for QPEs, this study suggests it could explain at least some of them.
In 2023, astronomers used the Chandra and Hubble telescopes to study the debris from the TDE after it occurred. They took Chandra observations three times, spaced about 4 to 5 hours apart, over 14 hours. They found a weak signal in the first and last observations but a strong signal in the middle.
Scientists then used NASA’s Neutron Star Interior Composition Explorer (NICER) to observe AT2019qiz for repeated X-ray bursts closely. They found that AT2019qiz erupts approximately every 48 hours. Observations from NASA’s Neil Gehrels Swift Observatory and India’s AstroSat telescope confirmed this finding.
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The ultraviolet data from Hubble, collected at the same time as the Chandra observations, helped scientists determine the size of the disk around the supermassive black hole. They discovered that the disk had grown large enough that any object orbiting the black hole and completing an orbit in about a week or less would collide with the disk, causing eruptions.
This discovery is essential for finding more quasi-periodic eruptions linked to tidal disruptions. If more of these events are identified, astronomers could better measure the number of objects in close orbits around supermassive black holes and their distances. Some of these objects might be excellent targets for future gravitational wave observatories.
Journal Reference:
- M. Nicholl, D. R. Pasham, A. Mummery et al. Quasi-periodic X-ray eruptions years after a nearby tidal disruption event. Nature. DOI: 10.48550/arXiv.2409.02181
