Jul 12 – 23, 2021
Europe/Berlin timezone

Transient Source for the Highest Energy Galactic Cosmic Rays

Jul 13, 2021, 12:00 PM
1h 30m


Talk CRI | Cosmic Ray Indirect Discussion


Glennys Farrar (New York University)


We analyze the Auger dipole anisotropy measurements below 8 EeV, to expose the existence of an individual source of the Galactic cosmic rays above $10^{17}$ eV. The source is incompatible with being in the direction of the Galactic center by a $\chi^2$/dof > 6. Interpreting the amplitude and direction of the Galactic HE Dipole in terms of a transient, we find:
a) The amplitude of the Galactic VHE dipole constrains the ratio of source distance and time since the transient event occurred.
b) The Galactic VHE dipole is compatible with production in a transient event in the Galactic plane which occurred about 30 kyr ago at a distance of about 1 kpc. A SN remnant and pulsar consistent with being the relics of this event are identified.
c) The peak rigidity of these VHE Galactic CRs is about 0.1 EV.
d) For reasonable estimates of the diffusion coefficient of the GMF, the energy emitted in CRs above 100 PeV by the transient Galactic source is about $10^{44-45}$ ergs —compatible with acceleration in the converging-flow shock of a core-collapse supernova exploding into the wind of a massive binary companion.

The estimated rate of such events in the Galaxy as a whole is compatible with the inferred space-time separation of this event. Comparable transient events in galaxies throughout the Universe may be an important source of astrophysical neutrinos. Implications and tests of this hypothesis for the origin of the highest energy Galactic cosmic rays will be discussed.


Galactic Cosmic Rays;
Astrophysical Neutrinos;
Massive Binaries;
Particle Acceleration;

Subcategory Theoretical Results

Primary author

Glennys Farrar (New York University)


Chen Ding (New York University) Marco Muzio

Presentation materials