Astronomers spotted the highest energy light ever seen from a pulsar

Astronomers have spotted extraordinarily high-energy gamma rays coming from a pulsar. The terribly excessive energy of this radiation challenges our fashions of those unusual stars and the way they speed up particles.

Pulsars are quickly rotating neutron stars with highly effective magnetic fields. Astronomers have found hundreds of them, however solely 4 are recognized to emit gamma rays highly effective sufficient to be detected by ground-based telescopes. Of these 4, just one emits gamma rays made up of photons with energies increased than one teraelectronvolt (TeV) – about the kinetic energy of a flying mosquito, which is kind of a lot for a elementary particle. That one is named the Vela pulsar.

Arache Djannati-Ataï at Paris Cité University in France and his colleagues discovered that the Vela pulsar is much more uncommon than we thought. They noticed it with an array of telescopes in Namibia referred to as the High Energy Stereoscopic System, and so they discovered that it emits gamma rays with energies in extra of 20 TeV, about 20 occasions extra energetic than the highest-energy radiation spotted from every other pulsar.

Our present explanations of how pulsars speed up particles can’t fairly account for this. Plus, the method we detect gamma rays by way of different particles produced in interactions with Earth’s ambiance implies that they may have even increased energies than 20 TeV – we merely don’t have sufficient information to know for certain. “We are putting a lower limit on the energies of the highest-energy particles, and this is already challenging for existing models,” says Djannati-Ataï. “But even if we go beyond 20 TeV, for the moment we have no indication of a cutoff energy.”

There are two competing fashions of photon acceleration by pulsars, each involving high-energy electrons slamming into the lower-energy photons that make up gamma rays. The distinction comes right down to how these electrons are accelerated in the first place: both by being flung away from the pulsar on account of interactions with its magnetic discipline or whipped round to excessive speeds as they observe the pulsar’s speedy rotation. But every of these fashions is tough to reconcile with these newfound gamma rays with no obvious higher restrict to their energy. “How and where the electrons are accelerated – that is the question,” says Djannati-Ataï. Until we determine that out, we can’t totally perceive pulsars, how they have an effect on their environment or why the Vela pulsar is producing such unusually intense radiation.