Strong Evidence for Metagalactic Shock Waves at Redshifts Z∽2–3

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Explosions of quasars and young galaxies are believed to proceed at large redshifts - an assumption which is examined in the present work. When occured these explosions should create blast waves which are propagated in the metagalactic medium. The shock waves formed can produce, during radiative cooling stages, dense cold spherical shells around the epicentres of explosions. But even before that, at the stage of adiabatic expansion, each spherical shock wave front if it lies on the line of sight with a more distant quasar, can imprint into the quasar spectrum a specific absorption “doublet” with a distance petween the components (in the rest frame) Δλ0≲ 3 A. The components of each doublet have a small but the same equivalent width Wo ≲ 0.3 A, the ratio W0 / Δλo weakly depending on Wo. We demonstrate here that such doublets of Lyα lines are really present among the ‘Lyα forest’· in the absorption spectra of distant (z = 2–3) quasars which are now commonly believed to be of mostly intervening (and not intrinsic) origin.