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Session 64 - Globular Clusters.
Oral session, Tuesday, January 14
Piers 2/3,

[64.04] Luminosity Differences Between Halo Globular Clusters with Red and Blue Horizontal Branches

Luminosity Differences Between Halo Globular Clusters with Red and Blue Horizontal Branches

Sidney van den Bergh (HIA/DAO)

Halo globular clusters with red horizontal branches [(B-R)/(B+V+R)<-0.80] have = -4.82, compared to = -7.30 for halo clusters with blue and intermediate-color horizontal branches. A Kolmogorov-Smirnov test shows that there is only a 0.1% chance that the red and blue HB clusters with R_GC>10 kpc were drawn from the same parent population. This suggests that the luminosity function of halo globular clusters may have become fainter with time. Alternatively, it might be assumed that metal-rich halo clusters were formed with lower masses than metal-poor ones.

Program listing for Tuesday