Blue Massive Stars in NGC 55: A First Quantitative Study

Castro, N.; Herrero, A.; Garcia, M.; Trundle, C.; Bresolin, F.; Gieren, W.; Pietrzynski, G.; Kudritzki, R.-P.; Demarco, R.
Bibliographical reference

Highlights of Spanish Astrophysics V, Astrophysics and Space Science Proceedings. ISBN 978-3-642-11249-2. Springer-Verlag Berlin Heidelberg, 2010, p. 269

Advertised on:
2010
Number of authors
9
IAC number of authors
3
Citations
0
Refereed citations
0
Description
We present the first census of blue massive stars in NGC 55, a galaxy of the Sculptor group at 1.94 Mpc. This study is based on optical low-resolution spectra of approximately 200 objects taken with VLT-FORS2. We have performed the spectral classification of these objects. The estimated stellar radial velocities show general agreement with the existing HI rotational velocity data. A first qualitative study of the stellar metallicity suggests that its global distribution over NGC 55 is close to that of the LMC, as derived from previous studies of H II regions. We have also determined the stellar parameters of one star showing that the resolution and the quality of the spectra are reliable to perform a quantitative analysis.