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Taking advantage of a recent FORS2/VLT spectroscopic sample of ExtremeHorizontal Branch (EHB) stars in $\omega$ Cen, we isolate 38 spectra wellsuited for detailed atmospheric studies and determine their fundamentalparameters ($T_{\rm eff}$, log $g$, and log $N$(He)/$N$(H)) using NLTE, metalline-blanketed models. We find that our targets can be divided into threegroups: 6 stars are hot ($T_{\rm eff}$$\buildrel>\over\sim\ $ 45,000 K) H-richsubdwarf O stars, 7 stars are typical H-rich sdB stars ($T_{\rm eff}$$\buildrel<\over\sim\ $35,000 K), and the remaining 25 targets at intermediateeffective temperatures are He-rich (log $N$(He)/$N$(H)$ \buildrel>\over\sim\ $$-$1.0) subdwarfs. Surprisingly and quite interestingly, these He-rich hotsubdwarfs in $\omega$ Cen cluster in a narrow temperature range ($\sim$35,000 Kto $\sim$40,000 K). We additionally measure the atmospheric carbon abundanceand find a most interesting positive correlation between the carbon and heliumatmospheric abundances. This correlation certainly bears the signature ofdiffusion processes - most likely gravitational settling impeded by stellarwinds or internal turbulence - but also constrains possible formation scenariosproposed for EHB stars in $\omega$ Cen. For the He-rich objects in particular,the clear link between helium and carbon enhancement points towards a late hotflasher evolutionary history.

A Helium-Carbon Correlation on the Extreme Horizontal Branch in $\omega$ Centauri