Galactic fireworks of exploding stars formed gigantic cloud towers of Milky-Way
Currents of gas are flowing upwards and downwards from the core of our Milky Way galaxy plane, and were now detected and analyzed by astronomers from Australia, the USA, Italy and The Netherlands, who published their findings in the journal Nature today.
The scientists used the Parkes radio telescope in Australia to record the gamma-ray emitting outflows.And they are truly gigantic, the "cone-shaped lobes" extending 25,000 light-years outwards, which is half the radius of the entire Milky Way.
Even more astonishing is the enormous power contained in the outflows: "These outflows contain an extraordinary amount of energy - about a million times the energy of an exploding star," said the research team's leader, CSIRO's Dr Ettore Carretti.
Travelling at supersonic speeds of about 1000 kilometres a second, the outflows also carry strong magnetic fields, which were the key to find out the causes of the phenomenon. "The options were a quasar-like outburst from the black hole at the Galactic Centre, or star-power - the hot winds from young stars, and exploding stars," said team member Dr Gianni Bernardi.
The magnetic fields could be determined "by measuring a key property of the radio waves from the outflows - their polarisation," said team member Dr Roland Crocker of the Max-Planck-Institut fuer Kernphysik in Heidelberg, Germany, and the Australian National University.
The result was that the "galactic geysers" seem to be driven by many generations of stars forming and exploding in the tumultous Galactic Centre over the last hundred million years. Caretti states, "These findings tell us there is transport of a massive amount of energy and strong magnetic fields from the galactic center to the outskirts of the galaxy. It is an interaction we did not know about, and can transform our view of the galactic halo."