A double component in GRB 090618: a proto-black hole and a genuinely long gamma-ray burst

Context. The joint X-ray and gamma-ray observations of GRB 090618 by very many satellites offer an unprecedented possibility of testing crucial aspects of theoretical models. In particular, they allow us to test (a) in the process of gravitational collapse, the formation of an optically thick e+e−-baryon plasma self-accelerating to Lorentz factors in the range 200 < Γ < 3000; (b) its transparency condition with the emission of a component of 1053−54 baryons in the TeV region and (c) the collision of these baryons with the circumburst medium (CBM) clouds, characterized by dimensions of 1015−16 cm. In addition, these observations offer the possibility of testing a new understanding of the thermal and power-law components in the early phase of this GRB.