11. OTHER RELATED PHENOMENA

It is quite likely that other particles (in addition to -rays) are emitted in these events. Let f_x be the ratio of energy emitted in other particles relative to -rays. These particles will appear as a burst accompanying the GRB. The total fluence of a "typical" GRB observed by BATSE, F is 10^-7 ergs/cm², and the fluence of a "strong" burst is about hundred times larger. Therefore we should expect accompanying bursts with typical fluences of:

(137)

where E_x is the energy of these particles. This burst will be spread in time and delayed relative to the GRB if the particles do not move at the speed of light. Relativistic time delay will be significant (larger than 10 seconds) if the particles are not massless and their Lorentz factor is smaller than 10⁸! similarly a deflection angle of 10^-8 will cause a significant time delay.

In addition to the prompt burst we should expect a continuous background of these particles. With one 10⁵¹ ergs GRB per 10⁶ years per galaxy we expect ~ 10⁴ events per galaxy in a Hubble time (provided of course that the event rate is constant in time). This corresponds to a background flux of

(138)

For any specific particle that could be produced one should calculate the ratio f_x and then compare the expected fluxes with fluxes from other sources and with the capabilities of current detectors. One should distinguish between two types of predictions: (i) Predictions of the generic fireball model which include low energy cosmic rays [220], UCHERs [294, 295, 296] and high energy neutrinos [297] and (ii) Predictions of specific models and in particular the NS²M model. These include low energy neutrinos [277] and gravitational waves [35, 301].