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I discuss a scenario in which the ultraviolet (UV) upturn of giant early-typegalaxies (ETGs) is primarily due to helium-rich stellar populations that formedin massive metal-rich globular clusters (GCs) which subsequently dissolved inthe strong tidal field in the central regions of the massive host galaxy. Thesemassive GCs are assumed to show UV upturns similar to those observed recentlyin M87, the central giant elliptical galaxy in the Virgo cluster of galaxies.Data taken from the literature reveals a strong correlation between thestrength of the UV upturn and the specific frequency of metal-rich GCs in ETGs.Adopting a Schechter function parametrization of GC mass functions, simulationsof long-term dynamical evolution of GC systems show that the observedcorrelation between UV upturn strength and GC specific frequency can beexplained by variations in the characteristic truncation mass ${\cal{M}}_{\rmc}$ such that ${\cal{M}}_{\rm c}$ increases with ETG luminosity in a way thatis consistent with observed GC luminosity functions in ETGs. These findingssuggest that the nature of the UV upturn in ETGs and the variation of itsstrength among ETGs are causally related to that of helium-rich populations inmassive GCs, rather than intrinsic properties of field stars in massivegalactic spheroids. With this in mind, I predict that future studies will findthat [N/Fe] decreases with increasing galactocentric radius in massive ETGs,and that such gradients have the largest amplitudes in ETGs with the strongestUV upturns.

Dissolved Massive Metal-Rich Globular Clusters Can Cause the Range of UV Upturn Strengths Found among Early-type Galaxies