Intrigued by a bright line in a series of photos, a scientific team discovered that it was probably a supermassive black hole, ejected from its galaxy and traveling at very high speed. It leaves behind a myriad of stars spread over more than 200,000 light-years…
Astronomy never ends with its extreme events!
Sign in one line
Hubble, like any telescope, is sometimes subject to reflections, “flares” or lines caused on the images by passing satellites. So when astrophysicist Pieter van Dokkum and his team were looking for star clusters and saw this milky-white line, they at first mistook it for an artifact, a measurement error. Intrigued, they asked for confirmation by spectroscopy at the Keck Observatory (Hawaii), and the result exceeded their expectations. Emanating from a single galaxy, it is a veritable garland of stars, 200,000 light-years long. And the suspect responsible for this great upheaval is none other than a supermassive black hole, traveling at very high speed. ” It’s something we’ve never seen before “, explains the researcher from Yale University.
Black hole, shiny wake
Better still, this Indian file of stars, which follows the black hole of about 20 million solar masses, would be directly generated by the latter. While crossing a long cloud of intergalactic gas at very high speed (approximately 6.5 million km/h), the gigantic black hole contracts and ionizes the gases which has the effect, as for a shock wave, of heating them and , at these astronomical scales, to allow the appearance of small blue stars, new worlds formed behind it. ” What remains visible is the consequence of its passage. Like the wake behind a ship, we watch this line of stars behind the black hole », describes P. Van Dokkum. A distant phenomenon even on a cosmic scale: the light of this event took about 7.6 billion years to reach us!
I’m leaving like a prince
But then, what could have ejected a supermassive black hole from its host galaxy? The preferred scenario for the moment (it is, let us remember, a unique observation of its kind) is that of a merger between several galaxies, probably three. Over time, the supermassive black holes at their different centers ended up disturbing each other so much (like a simulation of the famous “three-body problem”) that one of them could be ejected at high speed. To the point of leaving so quickly that he leaves a starry firework behind him. And all of this in one go…
Source : hubblesite
9