‘Heartbeat’ of supermassive black hole 600M light-years away still beating since 2007 discovery: Scientists
Satellite observations were blocked by our Sun in 2011. In 2018, the ESA's XMM-Newton X-ray satellite was able to finally re-observe the black hole and the same repeated heartbeat could still be seen
Discovered over 12 years ago in 2007, the first confirmed ‘heartbeat’ of a supermassive black hole is still going strong, say scientists. The evidence comes from a specific type of X-ray pattern, nicknamed a heartbeat because of its resemblance to an electrocardiogram. As matter falls on to a black hole, it releases a tremendous burst of energy in a repetitive pattern. This type of rhythmic cycle closely resembles an electrocardiogram of a human heart. The black hole's heartbeat was detected at the center of a galaxy called RE J1034+396, which is approximately 600 million light-years from Earth. The signal from this galactic giant repeated every hour and this behavior was seen in several snapshots taken before satellite observations were blocked by our Sun in 2011.
Astronomers have now rediscovered the heartbeat. The European Space Agency's XMM-Newton X-ray satellite was able to finally re-observe the black hole in 2018 and they found that the same repeated heartbeat could still be seen. According to scientists, this is the most long-lived heartbeat ever seen in a black hole. It tells experts more about the size and structure close to its event horizon, that is, the space around a black hole from which nothing, including light, can escape. Supermassive black holes contain millions or even billions of suns' worth of mass. Nearly all large galaxies, including the Milky Way, contain at least one of the monsters at their core. They are millions, if not billions, of times as massive as the Sun. Astronomers can detect them by watching for their effects on nearby stars and gas.
The research team -- which includes experts from the National Astronomical Observatories, Chinese Academy of Sciences, China, and Durham University, UK -- will next conduct a comprehensive analysis of this intriguing signal and compare it with the behavior of stellar-mass black holes in the Milky Way. “This heartbeat is amazing. It proves that such signals arising from a supermassive black hole can be very strong and persistent. It also provides the best opportunity for scientists to further investigate the nature and origin of this heartbeat signal,” said lead author Dr Chichuan Jin from the National Astronomical Observatories in the analysis published in the journal Monthly Notices of the Royal Astronomical Society.
According to the researchers, matter falling on to a supermassive black hole as it feeds from the accretion disc of material surrounding it releases an enormous amount of power from a comparatively tiny region of space, but this is rarely seen as a specific repeatable pattern like a heartbeat. The time between beats can tell scientists about the size and structure of the matter close to the black hole's event horizon.
“The main idea for how this heartbeat is formed is that the inner parts of the accretion disc are expanding and contracting. The only other system we know which seems to do the same thing is a 100,000 times smaller stellar-mass black hole in our Milky Way, fed by a binary companion star, with correspondingly smaller luminosities and timescales. This shows us that simple scaling with black hole mass work even for the rarest types of behavior,” said co-author Professor Chris Done from the Durham University's Centre for Extragalactic Astronomy.