A kinematically hot population of young stars in the solar neighbourhood
  In the last three decades several hundred nearby members of young stellar
moving groups (MGs) have been identified, but there has been less systematic
effort to quantify or characterise young stars that do not belong to previously
identified MGs. Using a kinematically unbiased sample of 225 lithium-rich stars
within 100 pc, we find that only $50 \pm 10$ per cent of young ($\lesssim 125$
Myr), low-mass ($0.5<M/M_{\odot}<1.0$) stars, are kinematically associated with
known MGs. Whilst we find some evidence that six of the non-MG stars may be
connected with the Lower Centaurus-Crux association, the rest form a
kinematically "hotter" population, much more broadly dispersed in velocity, and
with no obvious concentrations in space. The mass distributions of the MG
members and non-MG stars is similar, but the non-MG stars may be older on
average. We briefly discuss several explanations for the origin of the non-MG
population.
