On the origin of galactic cosmic rays

TL;DR

This paper proposes that a relativistic jet from the Galactic center, active over 10 million years, accelerated protons to explain the current distribution of cosmic rays in the Galaxy, and links observed bubbles to this activity.

Contribution

It introduces a model where a past jet from the Galactic center accounts for cosmic ray origins and associated galactic bubbles, with specific timing estimates.

Findings

Jet power and spectrum match cosmic ray distribution

Bubbles are remnants of past jet activity

Jet activity lasted between 10 and 24 million years

Abstract

It is shown that the relativistic jet, emitted from the center of the Galaxy during its activity, possessed power and energy spectrum of accelerated protons sufficient to explain the current cosmic rays distribution in the Galaxy. Proton acceleration takes place on the light cylinder surface formed by the rotation of a massive black hole carring into rotation the radial magnetic field and the magnetosphere. Observed in gamma, x-ray and radio bands bubbles above and below the galactic plane can be remnants of this bipolar get. The size of the bubble defines the time of the jet's start, $\simeq 2.4\cdot 10^7$ years ago. The jet worked more than $10^7$ years, but less than $2.4\cdot10^7$ years.