Electrons with fingerprints: how to tell pulsars from dark matter ✛ ✎ ✦

Original: "Electrons and Positrons in Cosmic Rays"

arXiv:1303.6118 · 2013-03-25 · arXiv non-exclusive · independent analysis · 1 min

The ATIC instrument measured the cosmic electron spectrum so precisely that narrow peaks became visible — only nearby pulsars can create them, not dark matter.

The cosmic electron spectrum is like fingerprints at a crime scene. Particles arriving from space carry in their energies the traces of their sources. Earlier instruments saw this trace blurred, but recently a sharp image emerged: a high-precision spectrum measured by the ATIC instrument with a resolution of about 3%. And unexpected lines appeared on it — three peaks and three dips.

Dark matter annihilating with itself would produce a single broad, smooth trace. But several nearby pulsars, rapidly rotating neutron stars, can leave several narrow peaks, like a comb.

This fine structure in the spectrum is a decisive clue. It cannot be explained by dark matter, but arises naturally from several nearby pulsars. If other experiments confirm such structure, the mystery of the positron excess will be resolved in favor of pulsars.

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The ATIC instrument flew on a balloon around the South Pole three times, and in two flights (ATIC-2 and ATIC-4) the fine structure of the electron spectrum was reproduced down to details, despite different conditions.

Scientists

Enrico Fermi Ernest Rutherford Albert Einstein Barry Barish Kip Thorne Richard Feynman

Concepts

ultra high energy cosmic ray source cosmic ray composition positron particle acceleration astrophysical polarimetry axion dark matter pulsar electron positron pair photoelectron axion detection neutron stars radio interference polaron pulsar phenomena energy reconstruction asymmetric dark matter radio source synchrotron radiation anomaly pulsation neutron star light emission

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Electrons with fingerprints: how to tell pulsars from dark matter ✛ ✎ ✦