The MOSDEF survey: the mass–metallicity relationship and the existence of the FMR at z ∼ 1.5
The MOSDEF survey: the mass–metallicity relationship and the existence of the FMR at z ∼ 1.5
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DOI：
10.1093/mnras/stab1793
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发表时间：
2021-03
影响因子：
4.8
通讯作者：
M. Topping;A. Shapley;R. Sanders;M. Kriek;N. Reddy;A. Coil;B. Mobasher;B. Siana;W. Freeman;I. Shivaei;Mojegan Azadi;S. Price;G. Leung;T. Fetherolf;Laura de Groot-Laura-de Groot-2124568861;T. Zick;F. Fornasini;G. Barro;Jordan N. Runco
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作者：
M. Topping;A. Shapley;R. Sanders;M. Kriek;N. Reddy;A. Coil;B. Mobasher;B. Siana;W. Freeman;I. Shivaei;Mojegan Azadi;S. Price;G. Leung;T. Fetherolf;Laura de Groot-Laura-de Groot-2124568861;T. Zick;F. Fornasini;G. Barro;Jordan N. Runco
本文分析了利用多目标光谱仪进行深演化场探测的z <$1.5星系的静止光发射线比。使用复合光谱，我们调查的质量金属丰度关系（MZR）在z = 1.5，并测量其演变到z = 0。当使用基于N2线比率的气相金属丰度时，我们发现从z = 1.5到z = 0的MZR演化取决于恒星质量，在M*< $10^{9.75}\时，由$\Delta \rm log（\rm O/H）\sim 0.25$ dex演化，\mathrm{M}_{\odot }$降至$\Delta \rm log（\rm O/H）\sim 0.05$，M*$10^{10.5}\，\mathrm{M}_{\odot }$。相比之下，基于O3 N2的MZR在所有质量中显示出$\Delta \rm log（\rm O/H）\sim 0.30$的恒定偏移，与之前基于独立金属丰度指标的MOSDEF结果一致，并表明O3 N2为我们的z ≥ 1.5样品提供了更稳健的金属丰度校准。我们通过测量平均M*-特异性SFR和M*−$\log（\rm O3 N2）$关系的相关散射，研究了MZR对星星形成率（SFR）的二次依赖性。我们发现$\log（\rm O/H）$和sSFR偏移量之间存在一个关系，表明存在一个M*−SFR−Z关系，尽管意义有限。此外，我们发现我们的z <$1.5叠加层沿着z = 0金属丰度序列上，固定为μ = log（M*/M）− 0.6 × $\log（\rm SFR / M_{\odot } \，yr^{-1}）$，这表明z <$1.5叠加层可以用z = 0基本金属丰度关系（FMR）来描述。然而，使用不同的校准可以移动计算的金属丰度的本地FMR，表明适当的校准是必不可少的理解红移的金属丰度演化。最后，了解[N ii]/H α如何与星系性质成比例，对于精确描述混合的[N ii]和H α对未来利用低分辨率光谱（如欧几里得和罗马太空望远镜）进行大型巡天测量的红移和H α流量测量的影响至关重要。
We analyse the rest-optical emission-line ratios of z ∼ 1.5 galaxies drawn from the Multi-Object Spectrometer for Infra-Red Exploration Deep Evolution Field (MOSDEF) survey. Using composite spectra, we investigate the mass–metallicity relation (MZR) at z ∼ 1.5 and measure its evolution to z = 0. When using gas-phase metallicities based on the N2 line ratio, we find that the MZR evolution from z ∼ 1.5 to z = 0 depends on stellar mass, evolving by $\Delta \rm log(\rm O/H) \sim 0.25$ dex at M*< $10^{9.75}\, \mathrm{M}_{\odot }$ down to $\Delta \rm log(\rm O/H) \sim 0.05$ at M* ≳ $10^{10.5}\, \mathrm{M}_{\odot }$. In contrast, the O3N2-based MZR shows a constant offset of $\Delta \rm log(\rm O/H) \sim 0.30$ across all masses, consistent with previous MOSDEF results based on independent metallicity indicators, and suggesting that O3N2 provides a more robust metallicity calibration for our z ∼ 1.5 sample. We investigated the secondary dependence of the MZR on star formation rate (SFR) by measuring correlated scatter about the mean M*-specific SFR and M*−$\log (\rm O3N2)$ relations. We find an anticorrelation between $\log (\rm O/H)$ and sSFR offsets, indicating the presence of a M*−SFR−Z relation, though with limited significance. Additionally, we find that our z ∼ 1.5 stacks lie along the z = 0 metallicity sequence at fixed μ = log (M*/M⊙) − 0.6 × $\log (\rm SFR / M_{\odot } \, yr^{-1})$ suggesting that the z ∼ 1.5 stacks can be described by the z = 0 fundamental metallicity relation (FMR). However, using different calibrations can shift the calculated metallicities off of the local FMR, indicating that appropriate calibrations are essential for understanding metallicity evolution with redshift. Finally, understanding how [N ii]/H α scales with galaxy properties is crucial to accurately describe the effects of blended [N ii] and H α on redshift and H α fiux measurements in future large surveys utilizing low-resolution spectra such as with Euclid and the Roman Space Telescope.