Paper detail

Cosmic rays: extragalactic and Galactic

From the analysis of the flux of high energy particles, $E>3\cdot 10^{18}eV$, it is shown that the distribution of the power density of extragalactic rays over energy is of the power law, ${\bar q}(E)\propto E^{-2.7}$, with the same index of $2.7$ that has the distribution of Galactic cosmic rays before so called &#39;knee&#39;, $E<3\cdot 10^{15}eV$. However, the average power of extragalactic sources, which is of ${\cal E}\simeq 10^{43}erg \,s^{-1}$, at least two orders exceeds the power emitted by the Galaxy in cosmic rays, assuming that the density of galaxies is estimated as $N_g\simeq 1 Mpc^{-3}$. Considering that such power can be provided by relativistic jets from active galactic nuclei with the power ${\cal E}\simeq 10^{45} - 10^{46} erg \, s^{-1}$, we estimate the density of extragalactic sources of cosmic rays as $N_g\simeq 10^{-2}-10^{-3}\, Mpc^{-3}$. Assuming the same nature of Galactic and extragalactic rays, we conclude that the Galactic rays were produced by a relativistic jet emitted from the Galactic center during the period of its activity in the past. The remnants of a bipolar jet are now observed in the form of bubbles of relativistic gas above and below the Galactic plane. The break, observed in the spectrum of Galactic rays (&#39;knee&#39;), is explained by fast escape of energetic particle, $E>3\cdot 10^{15}eV$, from the Galaxy because of the dependence of the coefficient of diffusion of cosmic rays on energy, $D\propto E^{0.7}$. The obtained index of the density distribution of particles over energy, $N(E)\propto E^{-2.7-0.7/2}=E^{-3.05}$, for $E>3\cdot 10^{15}eV$ agrees well with the observed one, $N(E)\propto E^{-3.1}$. Estimated time of termination of the jet in the Galaxy is $4.2\cdot 10^{4}$ years ago.