Dispersion of speeds (Dmytro Demchenko, Nikita Babenko)

Measure of the deviation of the speed of cosmic. objects from cf. the speeds of the group of objects into which they enter. In statistical understanding D. with. have cf. the arithmetic squares of the deviations of the velocities of objects vi, from their cf. arithmetic values ​​$ {\ bar v} = (v_1 v_2 ... v_n) / n $, that is, D. s. equals $ (1 / n) \ sum \ limits_ {i = 1} ^ n (v_i - {\ bar v}) ^ 2 $, where n is the number of objects. In the literature on star astronomy D. p. often called the square root of the above expression, i.e. value, called probability standard mean square deviation. Distances between congestions of galaxies increase on Hubble to the law over time, but certain galaxies in congestions have own (peculiar) speeds. Of village of galaxies in congestions makes 300-1000 km/s.