Quantitative Spectroscopy of Supergiants in the Local Group Dwarf Galaxy
  IC 1613: Metallicity and Distance
  We present the spectral analysis of 21 blue supergiant stars of spectral type
late B to early A within the Local Group dwarf galaxy IC 1613 based on
VLT-FORS2 low resolution spectra. Combining our results with studies of early B
type blue supergiants we report a wide bi-modal distribution of metallicities
with two peaks around [Z] $\sim -0.50$ dex and [Z] $\sim -0.85$ dex. The
bi-modal distribution correlates with spatial location, when compared with
column densities of neutral hydrogen in IC 1613. While the low [Z] objects
appear in regions of relatively high ISM HI column densities or close to them,
the high [Z] supergiants are found in the central HI hole almost devoid of
hydrogen. This suggests varied chemical evolution histories of the young
stellar populations in IC 1613. Utilizing the Flux-Weighted Gravity-Luminosity
Relation (FGLR), we determine IC 1613's distance modulus as $m - M$ = 24.39
$\pm$ 0.11 mag. This value is in agreement within previous distance
measurements using the near-infrared period-luminosity relationship of Cepheids
and the tip of the red giant branch.
