The ARAUCARIA Project: VLT-FORS Spectroscopy of Blue Supergiants in NGC 3109-Classifications, First Abundances, and Kinematics
Abstract
We have obtained multiobject spectroscopy of luminous blue supergiants in NGC 3109, a galaxy at the periphery of the Local Group at ~1.3 Mpc. We present a detailed catalog including finding charts, V and I magnitudes, spectral classifications, and stellar radial velocities. The radial velocities are seen to trace the rotation curves obtained from studies of the H I gas. From quantitative analysis of eight B-type supergiants we find a mean oxygen abundance of 12+log(O/H)=7.76+/-0.07 (1 σ systematic uncertainty), with a median result of 7.8. Given its distance, we highlight NGC 3109 as the ideal example of a low-metallicity, dark-matter-dominated dwarf galaxy for observations with the next generation of ground-based extremely large telescopes.
Based on observations at the European Southern Observatory Very Large Telescope in program 171.D-0004.- Publication:
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The Astrophysical Journal
- Pub Date:
- April 2007
- DOI:
- arXiv:
- arXiv:astro-ph/0612114
- Bibcode:
- 2007ApJ...659.1198E
- Keywords:
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- galaxies: individual (DDO 236);
- Galaxies: Individual: NGC Number: NGC 3109;
- Galaxies: Stellar Content;
- Stars: Early-Type;
- Stars: Fundamental Parameters;
- Astrophysics
- E-Print:
- 42 pages, 19 figures (most reduced in size). Accepted for publication in ApJ. A copy with full res. &
