On Galaxy Formation from Primeval Universal Turbulence
Abstract
The problem of galaxy separation from the continuous matter background due to density fluctuations is reconsidered in the frame of the universal turbulence theory of primeval matter, following the general outline to the problem due to Ozernoy et al. In common with these authors, the principal omission consists in the neglect of the dissipative effects occurring in the turbulence. The main behaviour of the three border lines limiting the largest or external scale (line E), the smallest or internal scale (line I) of the turbulence, and representing the equality of the turbulence velocity with sound velocity (line S) is followed throughout the three main phases of the universe; the radiation universe phase (I), preceding the equality time when radiation density equals matter density; the ionized matter universe phase (Il), included between the equality time and the recombination time; and the neutral matter universe phase (III) following recombination time. The main physical assumptions are the validity of Kolmogoroff's law V 1118 between turbulent velocity V and turbulent scale length 1 for subsonic regime, and of the extended Kolmogoroff's law V 1 (n> 1/3) for the supersonic regime. The density fluctuations in the supersonic phase III are assumed to occur according to von Hoerner' law l3e+1 which is described by the same compressibility parameter n, as the corresponding velocityscale relation. This enables to derive the separation condition for galaxies. The results are at variance in several points in respect to those of Ozernoy and collaborators, especially concerning the behaviour of the largest scale limit E in phases II and III, and the determination of n. The whole scheme is in fact dependent on oniy three parameters, the maximum velocity of the turbulence VL, the actual mean density of the universe 0m and the value of n. It is found that by assuming the maximum turbulent velocity as equal to sound velocity, which is required in order to keep as wide as possible the scale length interval in which hierarchical turbulence is maintained at the end of phase II, one may reasonably fit the data concerning the maximum mass of galaxies, the mean angnlar momentum per unit mass of spiral galaxies, the power law connecting angnlar momentum per unit mass to mass and the separation time for galaxies, with values of osm 0.6 1029 g/cm8 and n 3/5. As a closing remark, the significance of clusters of galaxies in the frame of the turbulence theory is shortly outlined. Key words: cosmology  universal turbulence  galaxy formation
 Publication:

Astronomy and Astrophysics
 Pub Date:
 June 1972
 Bibcode:
 1972A&A....19..123D