X-ray From Shredded Stars Provide Close-up of 'Killer' Black Hole
Some 3.9 billion years ago an intense tidal pull of a killer black hole shredded a star, the X-ray echoes from the tidal disruption reached the Earth in 2011 now known as the Swift J1644+57 detected by NASA's Swift Satellite. Today, astronomers are studying data from Swift in order to understand the tidal disruptions and black holes. Thanks to NASA's new X-ray mapping technology, astronomers found an easier way of understanding the phenomena.
"While we don't yet understand what causes X-ray flares near the black hole, we know that when one occurs we can detect its echo a couple of minutes later, once the light has reached and illuminated parts of the flow," Erin Kara, an astrophysicist from NASA Goddard said in an interview.
"This technique, called X-ray reverberation mapping, has been previously used to explore stable disks around black holes, but this is the first time we've applied it to a newly formed disk produced by a tidal disruption," Kara added.
The death or obliteration of a star by a black hole, also known as a tidal disruption causes x-ray echoes and leaves debris after a star is "killed" and falls into a black hole. A new x-ray mapping techniques helped the astronomers in further understanding the Swift J1644+57 and other black holes in the universe. This helps the scientists to observe and measure the population of supermassive black holes that are otherwise, and most of the time, just a black spot in the universe. But the temporary X-ray and jets of materials from the obliterated star make a black hole visible and easier to observe.
NASA's Swift satellite monitors the outburst progress of shredded stars with the help of Japanese Suzaku Satellite and ESA's XMM-Newton Observatory. A new technique called the X-ray reverberation mapping is introduced to study the temporary discs formed around a black hole after the destruction of a star. By using X-ray flashes, the regions surrounding the black holes can be observed just like how a sonar sensor uses sound to study and map the ocean bed.
NASA scientists and their partners from the University of Maryland were the ones who thought of using X-ray reverberation mapping when looking at tidal disruptive events. "Much to my surprise, the results were amazing and I can see that we were looking at the structure of the inner accretion flow around a normally dormant black hole for the first time," Kara said in an interview. The x-ray echoes provided the astronomers a clear glimpse of a "killer" supermassive black hole for the first time.
With this new mapping technique using X-ray reverberation, researchers can now easily observe how stellar materials from a star can be caught by a "killer" black hole, spinning around its edges creating a temporary disc.
Today, astronomers used this technique to observe how stellar debris falls toward a black hole and to study both dormant and active black holes in the universe. According to astronomers, they can observe the movements, directions and stellar flares during tidal disruptions except for the spinning, but with the new mapping technique, they might be able to do so in the near future.