A large sample of low surface brightness disc galaxies from the SDSS – II. Metallicities in surface brightness bins
A large sample of low surface brightness disc galaxies from the SDSS – II. Metallicities in surface brightness bins
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DOI：
10.1111/j.1365-2966.2010.16891.x
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发表时间：
2010-04
影响因子：
4.8
通讯作者：
Y. Liang;G. Zhong;F. Hammer;X. Y. Chen;F. Liu;D. Gao;J. Hu;L. Deng;B. Z. Naoc;
中科院分区：
文献类型：
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作者：
Y. Liang;G. Zhong;F. Hammer;X. Y. Chen;F. Liu;D. Gao;J. Hu;L. Deng;B. Z. Naoc;
我们研究了选自斯隆数字巡天数据版本 4 (SDSS-DR4) 主星系样本的大量低表面亮度星系 (LSBG) 样本的光谱特性 [B 波段中心表面亮度 μ0(B) > 22 mag arcsec -2 ]。同时还选择了盘主导的高表面亮度星系[HSBG，μ0(B) < 22 mag arcsec -2 ]的大样本进行比较。为了更详细地研究它们，这些样本星系根据μ0(B)（单位为mag arcsec -2 ）进一步分为四个子组：极低表面亮度星系（vLSBGs）（24.5–22.75）、中低表面亮度星系（iLSBGs）（22.75–22.0）、中高表面亮度星系（iHSBGs） (22.0–21.25) 和极高表面亮度星系 (vHSBG) (<21.25)。光谱发射线比率的诊断图显示，所有四个亚组的活动星系核部分都很小（<9%）。进一步选择光谱观测质量较好的21 032个恒星形成星系，研究其尘埃消光、强线比、金属丰度和恒星质量-金属丰度关系。与其他子群相比，vLSBG 具有较低的消光值，并且富含金属和质量较小的星系。我们的 LSBG 的氧丰度并不像文献中研究的 LSBG 中 H II 区域的氧丰度那么低，这可能是因为我们的样品更发光，并且因为使用了不同的金属丰度校准。我们发现 vLSBG、iLSBG 和 iHSBG 的 12 + log(O/H) 和 μ0(B) 之间存在相关性，但表明这可能是 μ0(B) 和恒星质量之间的相关性以及众所周知的质量-金属丰度关系的结果。这个大样本表明，LSBG 在金属丰度和恒星质量方面跨越了很宽的范围，并且它们几乎位于正常星系的恒星质量与金属丰度以及 N/O 与 O/H 关系上。这表明 LSBG 和 HSBG 的恒星形成和化学富集历史并没有显着不同。
We study the spectroscopic properties of a large sample of low surface brightness galaxies (LSBGs) [with B-band central surface brightness μ0(B) > 22 mag arcsec −2 ] selected from the Sloan Digital Sky Survey Data Release 4 (SDSS-DR4) main galaxy sample. A large sample of disc-dominated high surface brightness galaxies [HSBGs, with μ0(B) < 22 mag arcsec −2 ] are also selected for comparison simultaneously. To study them in more details, these sample galaxies are further divided into four subgroups according to μ0(B) (in units of mag arcsec −2 ): very low surface brightness galaxies (vLSBGs) (24.5–22.75), intermediate low surface brightness galaxies (iLSBGs) (22.75–22.0), intermediate high surface brightness galaxies (iHSBGs) (22.0–21.25) and very high surface brightness galaxies (vHSBGs) (<21.25). The diagnostic diagram from spectral emission-line ratios shows that the active galactic nucleus fractions of all the four subgroups are small (<9 per cent). The 21 032 star-forming galaxies with good-quality spectroscopic observations are further selected for studying their dust extinction, strong-line ratios, metallicities and stellar mass–metallicity relations. The vLSBGs have lower extinction values and have less metal-rich and massive galaxies than the other subgroups. The oxygen abundances of our LSBGs are not as low as those of the H II regions in LSBGs studied in literature, which could be because our samples are more luminous, and because of the different metallicity calibrations used. We find a correlation between 12 + log(O/H) and μ0(B) for vLSBGs, iLSBGs and iHSBGs but show that this could be a result of correlation between μ0(B) and stellar mass and the well-known mass–metallicity relation. This large sample shows that LSBGs span a wide range in metallicity and stellar mass, and they lie nearly on the stellar mass versus metallicity and N/O versus O/H relations of normal galaxies. This suggests that LSBGs and HSBGs have not had dramatically different star formation and chemical enrichment histories.