Researchers have observed the first-ever heartbeat of a supermassive black hole over the last ten years and confirmed that it is still going strong. X-ray satellite observations registered the repeated beat after its signal has been obscured by the Sun for a few years.
Astronomers said this is the most long-lived heartbeat ever discovered in a black hole and helps us better understand the dimension and structure close to its event horizon, which is the space surrounding a black hole from which not even light can escape.
A Surprising Discovery
The study, led by the National Astronomical Observatories, Chinese Academy of Sciences in China, and Durham University in the U.K., has been published in the journal Monthly Notices of the Royal Astronomical Society.
The black hole’s heartbeat was first found in 2007 at the center of a galaxy named RE J1034+396, which is located about 600 million light-years from Earth. The signal coming from this galactic body repeated every hour, with the behavior being observed in a few previous images captured by a satellite, before being blocked by our Sun in 2011.
In 2018, the ESA‘s XMM-Newton X-ray satellite was able to resume its watch over the black hole, and to researchers’ surprise, the same repeated heartbeat could still be observed. The matter collapsing on a supermassive black hole as it consumes material from the accretion disc surrounding it discharges a massive amount of power from a relatively tiny region of space, but this is rarely seen as a particular repeatable pattern resembling a heartbeat.
The time between beats can help astronomers learn more about the size and structure of the matter located close to the black hole’s event horizon.
Professor Chris Done, from Durham University’s Centre for Extragalactic Astronomy, collaborated on the discoveries with Professor Martin Ward from Temple Chevallier Chair of Astronomy.
Professor Done said: “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 scalings with black hole mass work even for the rarest types of behavior.”
Lead author Dr. Chichuan Jin of the National Astronomical Observatories, Chinese Academy of Sciences, said: “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.”
The next step in the observations is to carry out a thorough examination of this intriguing signal and compare it with the activity of stellar-mass black holes in the Milky Way.