Spectroscopic study of blue compact galaxies V. oxygen abundance and the metallicity-luminosity relation
Spectroscopic study of blue compact galaxies V. oxygen abundance and the metallicity-luminosity relation
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DOI：
10.1051/0004-6361:20041945
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发表时间：
2005-07
期刊：
影响因子：
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通讯作者：
F. Shi;X. Kong;Cheng Li;F. Cheng
中科院分区：
文献类型：
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作者：
F. Shi;X. Kong;Cheng Li;F. Cheng
这是研究蓝色致密星系（BCG）样本的恒星成分、星星形成历史、星星形成速率和金属丰度的系列论文中的第五篇。基于我们高质量的地基光谱观测，我们已经确定了我们样品中72个恒星形成BCGs的电子温度，电子密度，氮丰度和氧丰度，使用不同的氧丰度指标。氧丰度范围为7.15 - 8.2，显然是12 + log（O/H）< 8.2的初级核合成产物。为了评估不同氧丰度指标之间可能存在的系统差异，我们比较了Te法、R23法、P法、N2法和O3 N2法获得的BCGs的氧丰度。来自Te方法的氧丰度是系统地低于0.1-0.25德克斯比那些来自强线经验丰度指标，与以前的研究区域样品的基础上一致。我们证实了在大范围的丰度和光度的BCGs的金属性光度关系的存在。我们的星系样本表明，亮星系的金属度-光度关系的斜率（~-0.05）比矮星系的金属度-光度关系的斜率（~-0.17）稍浅。发现本星系的金属度-光度关系与中等红移星系的金属度-光度关系存在偏移。这表明，在高红移的发射线星系的金属丰度-光度关系被移位到低丰度，高光度，或两者兼而有之。
This is the fifth paper in a series studying the stellar components, star formation histories, star formation rates and metallicities of a blue compact galaxy (BCG) sample. Based on our high-quality ground-based spectroscopic observations, we have determined the electron temperatures, electron densities, nitrogen abundances and oxygen abundances for 72 star-forming BCGs in our sample, using different oxygen abundance indicators. The oxygen abundance covers the range 7.15 8.2 and apparently a product of primary nucleosynthesis for 12 + log (O/H)< 8.2. To assess the possible systematic differences among different oxygen abundance indicators, we have compared oxygen abundances of BCGs obtained with the Te method, R23 method, P method, N2 method and O3N2 method. The oxygen abundances derived from the Te method are systematically lower by 0.1-0.25 dex than those derived from the strong line empirical abundance indicators, consistent with previous studies based on region samples. We confirm the existence of the metallicity-luminosity relation in BCGs over a large range of abundances and luminosities. Our sample of galaxies shows that the slope of the metallicity-luminosity relation for the luminous galaxies (~-0.05) is slightly shallower than that for the dwarf galaxies (~-0.17). An offset was found in the metallicity-luminosity relation of the local galaxies and that of the intermediate redshift galaxies. It shows that the metallicity-luminosity relation for the emission line galaxies at high redshift is displaced to lower abundances, higher luminosities, or both.