New images taken from NASA's Chandra X-ray Observatory show a spectacular jet that emanates from a black hole in the centre of the galaxy and extends across 300,000 years toward a brilliant hotspot and a counter jet pointing in the opposite direction.The Pictor A galaxy is located nearly 500 million light years from Earth and contains a supermassive black hole at its centre.A huge amount of gravitational energy is released as material swirls towards the event horizon, the point of no return for infalling material.This energy produces an enormous beam, or jet, of particles travelling at nearly the speed of light into intergalactic space.To obtain images of this jet, scientists used Chandra observatory at various times over 15 years.The jet in Pictor displays continuous X-ray emission over a distance of 300,000 light years.By comparison, the entire Milky Way is about 100,000 light years in diameter.
Because of its relative proximity and ChandraÂ’s ability to make detailed X-ray images, scientists can look at detailed features in the jet and test ideas of how the X-ray emission is produced.In addition to the prominent jet seen pointing to the right in the image, researchers report evidence for another jet pointing in the opposite direction, known as a "counterjet".
While tentative evidence for this counterjet had been previously reported, these new Chandra data confirm its existence.
The detailed properties of the jet and counterjet observed with Chandra show that their X-ray emission likely comes from electrons spiraling around magnetic field lines, a process called synchrotron emission.In this case, the electrons must be continuously re-accelerated as they move out along the jet. How this occurs is not well understood.A paper describing these results is forthcoming in the journal Monthly Notices of the Royal Astronomical Society.