Emission Lines in the Near-infrared Spectra of the Infrared Quintuplet
  Stars in the Galactic Center
  We report the detection of a number of emission lines in the 1.0--2.4~$\mu$m
spectra of four of the five bright infrared dust-embedded stars at the center
of the Galactic center's Quintuplet Cluster. Spectroscopy of the central stars
of these objects is hampered not only by the large interstellar extinction that
obscures all objects in the Galactic center, but also by the large amounts of
warm circumstellar dust surrounding each of the five. The pinwheel morphologies
of the dust observed previously around two of them are indicative of Wolf-Rayet
colliding wind binaries; however, infrared spectra of each of the five have
until now revealed only dust continua steeply rising to long wavelengths and
absorption lines and bands from interstellar gas and dust. The emission lines
detected, from ionized carbon and from helium, are broad and confirm that the
objects are dusty late-type carbon Wolf-Rayet stars.
