Details

Autor(en) / Beteiligte

• Papaderos, P.
• Guseva, N. G.
• Izotov, Y. I.
• Noeske, K. G.
• Thuan, T. X.
• Fricke, K. J.

Titel

New southern blue compact dwarf galaxies in the 2dF Galaxy redshift survey

Ist Teil von

• Astronomy and astrophysics (Berlin), 2006-10, Vol.457 (1), p.45-59

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2006

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Aims.Aiming to find new extremely metal-deficient star-forming galaxies we extracted from the Two-Degree Field Galaxy Redshift Survey (2dFGRS) 100 K Data Release 14 emission-line galaxies with relatively strong [O iii] λ4363 emission. Methods.Spectroscopic and photometric studies of this sample and, in addition, of 7 Tololo and 2 UM galaxies were performed on the basis of observations with the ESO 3.6 m telescope. Results.All sample galaxies qualify with respect to their photometric and spectroscopic properties as blue compact dwarf (BCD) galaxies. Additionally, they show a good overlap with a comparison sample of ~100 well-studied emission-line galaxies on the $12+\log{\rm (O/H)}$ vs. log(Ne/O), log(Ar/O) and log(Fe/O) planes. From the analysis of the 2dFGRS subsample we report the discovery of two new extremely metal-deficient BCDs with an oxygen abundance $12+\log{\rm (O/H)}$ ≤ 7.6 and of another seven galaxies with $12+\log{\rm (O/H)}$ $\la$ 7.8. Furthermore, we confirm previous oxygen abundance determinations for the BCDs Tol 1304-353, Tol 2146-391, UM 559 and UM 570 to be $12+\log{\rm (O/H)}$ ≤ 7.8.