Universal Peaks Ratio In The Spectral Energy Density Of Double Hump Blazars, Gamma Ray Bursts, And Microquasars

Abstract: The peak frequencies of the two broad humps evident in the spectral energy density of blazars (SED) are time dependent and vary a lot between different blazars. However, their ratio in most blazars, appears to be almost universal and equal to $m_e c^2/4(1+z) \epsilon_p$ to a good approximation, where $m_e$ is the electron mass, $\epsilon_p$ is the peak energy of the cosmic microwave background radiation, and $z$ is the redshift of the blazar. We discuss a possible origin of such a universal ratio in blazars and gamma ray bursts (GRBs). We point out a possible connection between the knee in the energy spectrum of cosmic ray electrons and the maximal peak energies of the two broad humps in the SED of high-energy peaked blazars.