the night of April 18, 2015 was stirred to astrophysicist Evan Keane: the middle of the night, his phone began to s’ shake in all directions. All his colleagues called him to tell him that the Parkes Radio Telescope in Australia had detected a “fast radio burst,” or “fast radio burst” (FRB): “Evan, wake up! There was a FRB! “. He had to act quickly: “The goal was between the time when the wave hit the telescope and when we knew it no more months but either instantaneous,” says Evan Keane BBC .
Bingo, we found where does the radio burst
one can imagine Evan Keane and his colleagues to go throw their pajamas enable all optical telescopes in the corner. For all the mystery of these radio bursts was there: we had already saved – just 16 were recorded in the past – but we never had been able to determine the precise origin. This had evidently given way to more or less hazy theories up large text messages sent by aliens intergalactic phones equipped with …
But this time, astrophysicists have been rapid: within two hours after recording the start, the most powerful optical telescopes were pointed towards the sky. Bingo in the direction whence came the signal, they find that the galaxy has probably issued. “This is an event for the first time the host galaxy was probably identified within which this phenomenon occurred,” said Aurelien Barrau, a research professor at Subatomic Physics and Cosmology Laboratory (CNRS / Grenoble University Alps / Grenoble INP).
“Moving from oddity to science”
the culprit would be an elliptical galaxy 6 billion light years from Earth (one light year corresponds to 9.461 billion kilometers). This galaxy is off about 70,000 light years and its mass is equivalent to 100 billion stars the size of the Sun, says Evan Keane in the study published Wednesday in the journal Nature
“Knowing where does this radio burst to switch from the oddity of science: it is now no longer a mystery but a physical phenomenon that can be described,” s’ Aurélien Barrau enthusiasm.
But what has happened in this very very very distant galaxy to cause such a disturbance radio waves to billions of light years? Thereupon, there is no certainty. Several theories are circulating, but this time it is likely that one is dealing with a collision of neutron stars. “The signal lasted a short time, it was a brief burst, so that means that its source is likely to be very compact, which is the case of neutron stars,” said Aurelien Barrau.
this is currently the most credible hypothesis, but for astrophysicists is ultimately not the most important in this observation. “The scoop is less than the signal that it will be useful to probe some of the dark matter in the universe,” says Aurélien Barrau. Normal and dark matter, it is a sacred mystery. Its component made of conventional particles is about 5% of the energy that is our universe, 10 times more than the stars.
The recipe for cosmic soup
Our radio wave crossed this normal dark matter to get to us. And now we know the path it has taken, we will be able to calculate what has retained during the journey. “While strolling through intergalactic space, the radio burst was spread by electrons. By measuring the spreading of the signal, we come to measure the amount of a part of the dark matter that separates us from the source. We will thus be able to know the distribution and the nature of this dark matter, “says Aurélien Barrau.
With several radio bursts that are sure to be observed in the future, we could even establish a three-dimensional map this dark matter that is the main component of the universe. And learn about the recipe for the great cosmic soup in which we live
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