Figure 1 : Simulations for the ultraviolet data.

From: Rapidly rotating second-generation progenitors for the ‘blue hook’ stars of ω Centauri

Figure 1

Grey dots are the observed stars in ω Cen. Tracks plotted on the blue hook in a are: for M = 0.466M and Y = 0.37 (black); for 0.489M, Y = 0.25, standard Mc (green); and for M = 0.466M and Y = 0.37, Mc increased by 0.04M (magenta). Models have Xenv-in = 0.06. Also shown are the zero-age horizontal branch for Y = 0.37 (dashed black) and the 0.471M track (dotted black). Labels indicate bolometric distance modulus (mM)0 and reddening E(BV) adopted for the comparison. b, Simulation with a late-flash mixture of Xenv-in stars for Y = 0.37 (see text for the details of the chemistry, labels at the top). Comparisons with data are shown in the histograms on the left (blue hook, blue triangles) and right (extreme horizontal branch, red squares) side. On the histograms, 1σ Poisson errors are shown with respect to the counts N. c, Simulation resulting from coupling dynamics and evolution (same mixture of Xenv-in). Colour code and comparisons as in b.