A super-massive black hole flying out of its home galaxy may have been spotted by the Chandra X-ray telescope.
Marianne Heida, of the University of Utrecht in the Netherlands, was comparing galaxies from the Sloan Digital Sky Survey database with X-ray sources observed by Chandra, looking for matches where the X-ray source was not at the centre of the galaxy in question (black holes are thought to exist at the centre of most galaxies).
In a paper to be published in the Monthly Notices of the Royal Astronomical Society, Heida and her colleagues write that one source they spotted is “a strong candidate” for something called a “recoiling Super-Massive Black Hole” (pre-print).
These are predicted to result from the merging of two black holes, resulting in one large black hole that flies out of the home galaxy at high speed, because of the rotation of the two smaller black holes before their merger.
It is also possible, says the paper, that the observation is also a very blue type of supernova or an ultra-luminous X-ray source which also has a very bright optical counterpart.
“We have found even more of this strange class of X-ray sources,” says Heida (press release). “However, for these objects we first of all need accurate measurements from NASA’s Chandra satellite to pinpoint them more precisely.”
Image: in this Hubble picture the black circle indicates the galaxy centre, with the red circle showing the possible ejected black hole.