Speaker
Prof.
Istomin Yakov
(Moscow Institute Physics and Technology)
Description
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 'knee',
$E<3\cdot 10^{15}eV$. 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 ('knee'), 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.
| Registration number following "ICRC2015-I/" | 1010 |
|---|---|
| Collaboration | -- not specified -- |
Author
Prof.
Istomin Yakov
(Moscow Institute Physics and Technology)
