Changing physical conditions in star-forming galaxies between redshifts 0 < z < 4: [O iii]/H β evolution
Changing physical conditions in star-forming galaxies between redshifts 0 < z < 4: [O iii]/H β evolution
复制标题
红移 0 < z < 4 之间恒星形成星系中物理条件的变化：[O iii]/H β 演化
DOI：
10.1093/mnras/stw1181
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发表时间：
2016
影响因子：
4.8
通讯作者：
R. Bowler
中科院分区：
文献类型：
--
作者：
F. Cullen;M. Cirasuolo;L. Kewley;R. McLure;J. Dunlop;R. Bowler
我们研究了一个红移范围为0<；z<；4的星系样本的[OIII]/Hb星云发射线比的红移演化。我们将观测到的演化与一套理论模型进行了比较，这些模型解释了具有红移的恒星形成星系中化学丰度、电离参数和星际介质(ISM)压强的独立演化。考虑到组合数据集中的选择效应，我们表明，红移到更高的[OIII]/Hb比值的演化是一种真正的物理效应，这可以用一个模型来最好地解释，在该模型中，电离参数从本地恒星形成星系的典型平均值提高，同时ISM气压可能增加。我们排除了观察到的[OIII]/Hb演化纯粹是由于金属丰度演化的可能性。我们讨论了这些结果对使用局域经验金属丰度校准来测量高红移金属丰度的意义，并简要讨论了我们的结果可能的理论意义。
We investigate the redshift evolution of the [OIII]/Hb nebular emission line ratio for a sample of galaxies spanning the redshift range 0 < z < 4. We compare the observed evolution to a set of theoretical models which account for the independent evolution of chemical abundance, ionization parameter and interstellar-medium (ISM) pressure in star-forming galaxies with redshift. Accounting for selection effects in the combined datasets, we show that the evolution to higher [OIII]/Hb ratios with redshift is a real physical effect which is best accounted for by a model in which the ionization parameter is elevated from the average values typical of local star-forming galaxies, with a possible simultaneous increase in the ISM pressure. We rule out the possibility that the observed [OIII]/Hb evolution is purely due to metallicity evolution. We discuss the implications of these results for using local empirical metallicity calibrations to measure metallicities at high redshift, and briefly discuss possible theoretical implications of our results.