Theoretical and observed UV energy distributions of 7 globular clusters

Abstract

A grid of synthetic UV spectra is computed and the effects of the various parameters are shown. A comparison with the integrated spectra of 7 globular clusters is made with satisfactory results, suggesting that constraints on the HB morphology and the chemical composition may be achieved on the basis of the UV fluxes alone. A spread in the observed UV fluxes similar to that discovered by ANS is found, clearly requiring a second parameter to describe HB morphologies. No UV excesses are found in the core of two X-rays clusters. The presence of UV-bright stars is investigated.