AAS Nova
Relativistic jet
A beam of matter fired from near a black hole at very nearly the speed of light.
Some accreting black holes launch narrow jets along their rotation axes, driven by magnetic fields wound up by the disc and the spin. The jets can extend for hundreds of thousands of light years — far beyond the galaxy — and they carry enough energy to heat the gas of a whole cluster and shut down its star formation. The jet from M87 was photographed in 1918 and not understood for another sixty years.
Where it has come up lately
Related terms
Event horizon
The boundary around a black hole past which nothing gets out — not a surface, but a point of no return.
Accretion disc
The flat, ferociously hot spiral of matter falling onto a compact object.
Singularity
The point where our description of gravity stops producing meaningful answers.
Schwarzschild radius
How small you would have to squeeze something to make it a black hole.
Questions
What is Relativistic jet?
A beam of matter fired from near a black hole at very nearly the speed of light.
Why does it matter?
The jets can extend for hundreds of thousands of light years — far beyond the galaxy — and they carry enough energy to heat the gas of a whole cluster and shut down its star formation. The jet from M87 was photographed in 1918 and not understood for another sixty years.