5.1. Models for The Energy Flow

The simplest mode of relativistic energy flow is in the form of kinetic energy of relativistic particles. A variant that have been suggested is based on the possibility that a fraction of the energy is carried by Poynting flux [224, 225, 226, 69, 227] although in all models the power must be converted to kinetic energy somewhere. The energy flow of ~ 10⁵⁰ ergs/sec from a compact object whose size is 10⁷cm requires a magnetic field of 10¹⁵Gauss or higher at the source. This large value might be reached in stellar collapses of highly magnetized stars or amplified from smaller fields magnethohydrodynamically [69]. Overall the different models can be characterized by two parameters: the ratio of the kinetic energy flux to the Poynting flux and the location of the energy conversion stage ( 10¹² cm for internal conversion or 10¹⁶ cm for external conversion). This is summarized in Table 5.1. In the following section we will focus on the simplest possibility, that is of a kinetic energy flux.