Volume 421, Number 2, July II 2004
|Page(s)||539 - 554|
|Published online||22 June 2004|
Main Astronomical Observatory, Ukrainian National Academy of Sciences, 27 Zabolotnoho str., Kyiv 03680, Ukraine
2 Universitäts – Sternwarte, Geismarlandstraße 11, 37083 Göttingen, Germany
3 Astronomy Department, University of Virginia, Charlottesville, VA 22903, USA
Corresponding author: Y. I. Izotov, firstname.lastname@example.org
Accepted: 29 March 2004
We present VLT spectroscopic observations with different spectral resolutions and different slit orientations of the two metal-deficient blue compact dwarf (BCD) galaxies Tol 1214–277 and Tol 65. The oxygen abundances in the brightest H ii regions of Tol 1214–277 and Tol 65 are found to be and , or /24. The nitrogen-to-oxygen abundance ratios in the two galaxies are log N/O = – and – and lie in the narrow range found for other most metal-deficient BCDs. The helium mass fraction derived in several H ii regions in both galaxies is consistent with a high primordial helium mass fraction, . We confirm the detection of the high-ionization forbidden emission line [Fe v] λ4227 in the spectrum of Tol 1214–277. Additionally, weak [Ne iv] λ4725, [Fe vi] λ5146, λ5177, and [Fe vii] λ5721, λ6087 emission lines are detected in the high-resolution spectrum of Tol 1214–277. The detection of these lines implies the presence of hard radiation with photon energy in the range ~4–8 Ryd. Emission lines are detected in the spectra of eight galaxies in the fields of Tol 1214–277 and Tol 65. Seven of these galaxies are background objects, while one galaxy has a redshift close to that of Tol 1214–277. Situated at a projected distance of ~14.5 kpc from Tol 1214–277, this galaxy is probably a companion of the BCD.
Key words: galaxies: starburst / galaxies: abundances / galaxies: individual: Tol 1214–277 / galaxies: individual: Tol 65
Based on observations obtained at the European Southern Observatory, Paranal, Chile (ESO Programs 63.P-0003 and 65.N-0642).
Tables 2–4 and 8 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/421/539
© ESO, 2004
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