Abstract
We use 1536 Vsin i measurements of evolved field stars in order to determine the q parameter from the named q-Maxwellian model (Soares et al. 2006, Physica A, 364, 413), a power-law type distribution function that adjusts the distribution of the projected rotational velocity. Then we compare the different distributions of Vsin i obtained for different B-V intervals with the distribution model using the Kolmogorov-Smirnov statistical test to find the best fit. Results revealed that, as overall trend, low B-V tends to exhibit q>1 values while q<1 for high B-V for all classes of stars under study. Specifically, this point indicates rotation distributions with long tails due to the percentage of stars with relatively high speed for low B-V, and tailless distributions for stars of high B-V. Furthermore, it is a general behavior that binaries present q values slightly higher than singles indicating that their rotation distributions are wider than the single ones. As another broad trend, binaries tend to have q<1 values later than their fellow-colors. In addition, there exists an inversion point in B-V, from which q>1 regime switches to q<1 regime, that is higher the more evolved is the luminosity class.
