A giant black hole in the center of a distant galaxy has recently been caught burping its lunch twice, expelling two powerful jets of high-energy particles.
The observation here confirms the theory that such galactic nuclei pass through cycles of disordered activity. Black holes do not stay there constantly gulping down the surrounding matter, in the same way that you do not spend all your day at the table.
When they are short of material, they go out, waiting for the opportunity of a next meal. This cycle of activity / inactivity had never been seen before. Inactive black holes have already been observed, others in the middle of a meal too, but never a single black hole eating then fasting, then eating again had been seen until now.
If we are used to the theory that nothing ever comes out of a black hole, it sometimes happens that one of them – a little too greedy – feasting on the surrounding matter, rejects part of it in space. Metaphorically, imagine a kind of cosmic burp. “Black holes are voracious eaters, but it also turns out they do not have very good table manners,” says researcher Julie Comerford, an astronomer at the University of Colorado at Boulder.
The black hole in question is a supermassive beast that you will find in the center of a galaxy called SDSS J1354 + 1327, or simply J1354, located about 800 light-years from Earth. This black hole here seems to be feasting on the matter emitted by a neighboring galaxy.
The Comerford team has combined images from the Chandra X-ray observatory and the Hubble Space Telescope to locate two emerging gas bubbles: one above and one below the black hole. The oldest one has been located 30,000 light years away from the black hole, while the most recent one is only 3,000 light-years away from it. These two “burps” were also issued about 100,000 years apart.
According to the theory, supermassive black holes would go through a cycle of feasts, alternating regurgitations and naps for a while. Locating such a cycle allows to punctuate the process. If 100,000 years apart may seem like a slow metabolism, it’s ultimately the opposite on a cosmic scale.