SCYON Abstract

Received on April 26 2007

The Blue Straggler Population of the Globular Cluster M5

Authors	B. Lanzoni (^1,2), E. Dalessandro (^1,2), F.R. Ferraro (¹), C. Mancini (³), G. Beccari (^2,4,5), R.T. Rood (⁶), M. Mapelli (⁷), and S. Sigurdsson (⁸)
Affiliation	(¹) Dip. Astro., Bologna (²) INAF-Oss. Astro., Bologna (³) Dip. Astro. e Scienza dello Spazio, Firenze (⁴) Dip. di Scienze della Comunicazione, Teramo (⁵) INAF-Oss. Astro. di Collurania, Teramo (⁶) Dep. of Astronomy and Astrophysics, The Pennsylvania State University (⁷) S.I.S.S.A., Via Beirut 2-4, Trieste (⁸) Astronomy Department, University of Virginia
Accepted by	Astrophysical Journal
Contact	barbara.lanzoni@bo.astro.it
URL	http://www.arxiv.org/abs/0704.0139
Links

Abstract

By combining high-resolution HST and wide-field ground based observations, in ultraviolet and optical bands, we study the Blue Stragglers Star (BSS) population of the galactic globular cluster M5 (NGC 5904) from its very central regions up to its periphery. The BSS distribution is highly peaked in the cluster center, decreases at intermediate radii and rises again outward. Such a bimodal distribution is similar to those previously observed in other globular clusters (M3, 47Tucanae, NGC6752). As for these clusters, dynamical simulations suggest that, while the majority of BSS in M5 could be originated by stellar collisions, a significant fraction (20-40%) of BSS generated by mass transfer processes in primordial binaries is required to reproduce the observed radial distribution. A candidate BSS has been detected beyond the cluster tidal radius. If confirmed, this could represent an interesting case of an "evaporating" BSS.