Red Supergiants as Cosmic Abundance Probes: The Sculptor Galaxy NGC 300
Bender, Ralf; Bonanos, Alceste Z.; Bresolin, Fabio; Bergemann, Maria; Williams, Stephen J.; Davies, Ben; Plez, Bertrand; Wegner, Michael; Kudritzki, Rolf; Evans, Chris; Gazak, J. Zachary; Patrick, Lee
United States, Germany, United Kingdom, France, Greece
Abstract
We present a quantitative spectroscopic study of 27 red supergiants (RSGs) in the Sculptor Galaxy NGC 300. J-band spectra were obtained using KMOS on the Very Large Telescope and studied with state of the art synthetic spectra including NLTE corrections for the strongest diagnostic lines. We report a central metallicity of [Z] = -0.03 ± 0.05 with a gradient of -0.083 ± 0.014 [dex/kpc], in agreement with previous studies of blue supergiants and H ii-region auroral line measurements. This result marks the first application of the J-band spectroscopic method to a population of individual RSG stars beyond the Local Group of galaxies and reveals the great potential of this technique.
Data collected under ESO Program ID 092.B-0088.