The spatial distribution of spectroscopic binaries and blue stragglers in the open cluster M67

Abstract

The authors examine the spatial distribution of spectroscopic binaries and blue stragglers in the old open cluster M67. They show that both the binaries and the blue stragglers are indeed more centrally concentrated than the 1.2 M_sun; main-sequence-turnoff stars. Furthermore, the spatial distributions of the binaries and blue stragglers are very similar. The authors show that the central concentration of the binaries and blue stragglers is consistent with a multimass isotropic equipartition King model fit to the cluster in which the binaries and blue stragglers are modeled by a relaxed 2 M_sun; component. Finally, the authors discuss the implications of these findings with regard to the origin of blue stragglers.