Intrinsic Metallicity Variation in the Intermediate Mass Type II
  Globular Cluster NGC 1261
  Globular Clusters (GCs) are now well known to almost universally show
multiple popu-lations (MPs). The HST UV Legacy Survey of a large number of
Galactic GCs in UV filters optimized to explore MPs finds that a small fraction
of GCs, termed Type II, also display more complex, anomalous behavior. Several
well-studied Type II GCs show intrinsic Fe abundance variations, suggesting
that the other, less well-studied, Type II GCs should also exhibit similar
behavior. Our aim is to perform the first detailed metallicity analysis of NGC
1261, an intermediate mass Type II GC, in order to determine if this object
shows an intrinsic Fe variation. We determined the Fe abundance in eight red
giant members using Magellan-MIKE and UVES-FLAMES high-resolution, high S/N
spectroscopy. The full range of [Fe/H] for the entire sample from the spectra
is from -1.05 to -1.43 dexwith an observed spread sigma_obs=0.133 dex. Compared
with the total internal error of Sigma_tot=0.06,this indicates a significant
intrinsic metallicity spread of Sigma_int=0.119 dex. We found a very similar
variation in [Fe/H] using an independent method to derive the atmospheric
parameters based on near-IR photometry. More importantly, the mean metallicity
of the five presumed normal metallicity stars is -1.37+/-0.02, while that of
the three presumed anomalous/highmetallicity stars is -1.18+/-0.09. This
difference is significant at the $\pm$2.4Sigma level. We find indications from
existing data of other Type II GCs that several of them presumedto have real
metallicity spreads may in fact posses none. The minimum mass required for a GC
to acquire an intrinsic Fe spread appears to be $\pm$10^5 Msun. We find no
strong correlation betwee nmass and metallicity variation for Type II GCs. The
metallicity spread is also independent of the fraction of anomalous stars
within the Type II GCs and of GC origin.
