Superstatistics and stellar rotation: Modeling velocity distributions in six stellar groups

Abstract

In the present study, we investigate the observed distribution of the projected rotational velocity for six different stellar groups: young-type and late-type (including the spectral classes F, G, and K), OB-type, A-type, B-type, and M-type. Our analysis shows that the distribution of projected rotational velocities for these stellar groups deviates from a Maxwellian distribution. Instead, it is better captured by a generalized statistical mechanics framework known as superstatistics. Within this framework, the distribution is modeled as a superposition of a locally Maxwellian distribution, whose width fluctuates over a large spatiotemporal scale according to a ${\chi }^2$ distribution. We identify a correlation between the mean rotational velocity and the parameters defining the distribution, specifically the number of degrees of freedom contributing to the fluctuations. This dependency highlights the intricate relationship between the rotational dynamics and the generalized statistical mechanics properties of stellar systems.