A Survey of CN and CH Variations in Galactic Globular Clusters from SDSS
  Spectroscopy
  We present a homogeneous survey of the CN and CH bandstrengths in eight
Galactic globular clusters observed during the course of the Sloan Extension
for Galactic Understanding and Exploration (SEGUE) sub-survey of the SDSS. We
confirm the existence of a bimodal CN distribution among RGB stars in all of
the clusters with metallicity greater than [Fe/H] = -1.7; the lowest
metallicity cluster with an observed CN bimodality is M53, with [Fe/H] ~ -2.1.
There is also some evidence for individual CN groups on the subgiant branches
of M92, M2, and M13, and on the red giant branches of M92 and NGC 5053.
Finally, we quantify the correlation between overall cluster metallicity and
the slope of the CN bandstrength-luminosity plot as a means of further
demonstrating the level of CN-enrichment in cluster giants. Our results agree
well with previous studies reported in the literature.
