Red Supergiants as Cosmic Abundance Probes: The Sculptor Galaxy NGC 300

J. Zachary Gazak , Rolf Kudritzki , Chris Evans , Lee Patrick , Ben Davies , Maria Bergemann , Bertrand Plez (1, 2) , Fabio Bresolin , Ben Bender , Michael Wegner (3) , Alceste Bonanos , Stephen Williams

1 Astrophysique Stellaire
2 LUPM - Laboratoire Univers et Particules de Montpellier
3 Institut für Biochemie [Erlangen]

We present a quantitative spectroscopic study of twenty-seven red supergiants in the Sculptor Galaxy NGC 300. J-band spectra were obtained using KMOS on the VLT 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 red supergiant stars beyond the Local Group of galaxies and reveals the great potential of this technique.

Domaines: Astrophysique galactique [astro-ph.GA]; Astrophysique [astro-ph]

J. Zachary Gazak, Rolf Kudritzki, Chris Evans, Lee Patrick, Ben Davies, et al.. Red Supergiants as Cosmic Abundance Probes: The Sculptor Galaxy NGC 300. The Astrophysical journal letters, 2015, 805 (2), pp.182. ⟨10.1088/0004-637X/805/2/182⟩. ⟨hal-01972061⟩