High-speed winds from an X-ray binary
(Credit: ESA – C. Carreau)
ESA’s XMM-Newton has discovered gas streaming away at a quarter of the speed of light from very bright X-ray binaries in two nearby galaxies.
“Imagine to do a complete round of the Earth in one second. Almost there…do two rounds of the Earth in 1 second. You got it? Yes? Excellent! Your speed was the same as the speed that I have spotted in these crazy objects known as Ultraluminous X-ray sources.”
What does this mean?
It means that a dark, compact object, namely a black hole or a neutron star, is sucking matter from a “poor” companion at a rate which goes beyond classical predictions…
Due to the rotation of the binary system, the accreted gas forms a disk around the dark object…a disk in which the gas makes a lot of friction…high enough to heat itself at temperature of million degrees…and it emits a huge amount of X-ray photons (from which the name “Ultraluminous X-ray source”). Think, in the X-ray energy band, this source, this little binary system is BRIGHTER THAN THE WHOLE GALAXY hosting it. How cool is that?
But this is only the beginning…
In the disk being formed around the hungry black hole, the gas start to lift up making it thicker and brighter. The more gas is accreted, the higher the luminosity of the gas….
All this X-ray light starts pushing the gas through a process known as radiation pressure.
Such a energy power is able to literally kick the gas which then escape with a tremendous velocity of seventy thousand kilometres per second, alias about one forth of the speed of the light. Can you imagine what effects will this wind have on the surrounding space? Mmh….hoovering like crazy….a massive vacuum cleaner!!!! But this story will be told afterwards….
The original press release from the European Space Agency (ESA) is highlighted in the link above. More technical detail is to be found in the paper that I published with my research team on the Nature magazine: