mollwollfumble said:
Tau.Neutrino said:
Halo Around a Pulsar could Explain Why We See Antimatter Coming from Space
Astronomers have been watching a nearby pulsar with a strange halo around it. That pulsar might answer a question that’s puzzled astronomers for some time. The pulsar is named Geminga, and it’s one of the nearest pulsars to Earth, about 800 light years away in the constellation Gemini. Not only is it close to Earth, but Geminga is also very bright in gamma rays.
more…
Geminga. Very famous. Size comparison of pulsar halo vs constellation. totally unexpected it to be anything near as big as this. Will read this later.
Great little article.
> So by the time cosmic rays reach Earth, astronomers can’t pinpoint their source. … Until 2017.
I had heard that this was coming.
> NASA’s Fermi Gamma-ray Space Telescope, NASA’s Alpha Magnetic Spectrometer … the High-Altitude Water Cherenkov Gamma-ray Observatory (HAWC) confirmed what some ground-based detections had found: a small but intense gamma-ray halo around Geminga. The HAWC detected energies in the halo structure of 5 – 40 TeV.
> Di Mauro is the lead author of a new study presenting these findings. The study is titled “Detection of a γ-ray halo around Geminga with the Fermi-LAT data and implications for the positron flux.” The paper is published in Physics Review.
> a vast oblong structure; a halo around Geminga. The high energy structure covered 20 degrees in the sky at 20 billion electron volts … Geminga’s halo is elongated partly because of the pulsar’s motion through space. … Geminga could be responsible for as much as 20% of the high-energy positrons that the AMS-02 experiment observed. Extrapolating from that to all of the cumulative pulsar emissions in the Milky Way, the team says that pulsars remain the best explanation for … all those positrons near Earth.
I’ll accept that.