Nonextensivity in the solar neighborhood

¹ Instituto de Educação, Ciência e Tecnologia do Rio Grande do Norte - 59550-000 João Câmara, RN, Brazil
² Departamento de Física, Universidade Federal do Rio Grande do Norte - 59072-970 Natal, RN, Brazil

^a danielbrito@dfte.ufrn.br
^b renan@dfte.ufrn.br

Received: 27 September 2011
Accepted: 16 November 2011

Abstract

In the present study, we analyze the radial-velocity distribution as a function of different stellar parameters such as stellar age, mass, rotational velocity and distance to the Sun for a sample of 6781 single low-mass field dwarf stars, located in the solar neighborhood. We show that the radial-velocity distributions are best fitted by q-Gaussians that arise within the Tsallis nonextensive statistics. The obtained distributions cannot be described by the standard Gaussian that emerges within Boltzmann-Gibbs (B-G) statistical mechanics. The results point to the existence of a hierarchical structure in phase space, in contrast to the uniformly occupied phase space of B-G statistical mechanics, driven by the q-Central Limit Theorem, consistent with nonextensive statistical mechanics.