论文标题
SDSS-IV漫画：探索N/O的本地扩展关系
SDSS-IV MaNGA: Exploring the local scaling relations for N/O
论文作者
论文摘要
我们首次使用$ 792765 $ $ 792765 $高信号与噪声比率的spaxels的样本，首次提出本地恒星质量表面密度，$ \ mathrm {σ_{*}} $与源自SDSS-IV漫画数据的N/O之间的关系。使用现象学建模和部分相关分析的组合，我们发现$ \ mathrm {σ_{*}} $仅在漫画spaxels中预测N/O不足以预测N/O，并且还需要额外依赖于本地星形的表面密度，$ \ Mathrm {c {σ_=σ_{sfr} $。此效果比12+log（o/h）在$ \ mathrm {σ_{sfr}} $上的依赖性$ 3 $。令人惊讶的是，我们发现本地N/O比例关系还取决于固定$σ_ {*} $的总星系恒星质量以及固定恒星质量处的星系大小。我们发现，即使在控制$ \ mathrm {σ_{*}} $和$ \ mathrm {σ_{sfr}} $的情况下，更紧凑的星系也更丰富氮。我们表明，N/O方差的$ \ sim50 \％$由总恒星质量和大小来解释。因此，星系中氮的进化不仅是由局部效应设置的，而且不仅仅是跟踪星系中氧气的积累。因此，N/O-O/H关系的精确形式对其得出的星系样品敏感。该结果对基于氮的强线金属性指标的普遍适用性提出了怀疑。
We present, for the first time, the relationship between local stellar mass surface density, $\mathrm{Σ_{*}}$, and N/O derived from SDSS-IV MaNGA data, using a sample of $792765$ high signal-to-noise ratio star-forming spaxels. Using a combination of phenomenological modelling and partial correlation analysis, we find that $\mathrm{Σ_{*}}$ alone is insufficient to predict the N/O in MaNGA spaxels, and that there is an additional dependence on the local star formation rate surface density, $\mathrm{Σ_{SFR}}$. This effect is a factor of $3$ stronger than the dependence of 12+log(O/H) on $\mathrm{Σ_{SFR}}$. Surprisingly, we find that the local N/O scaling relations also depend on the total galaxy stellar mass at fixed $Σ_{*}$ as well as the galaxy size at fixed stellar mass. We find that more compact galaxies are more nitrogen rich, even when $\mathrm{Σ_{*}}$ and $\mathrm{Σ_{SFR}}$ are controlled for. We show that $\sim50\%$ of the variance of N/O is explained by the total stellar mass and size. Thus, the evolution of nitrogen in galaxies is set by more than just local effects and does not simply track the build up of oxygen in galaxies. The precise form of the N/O-O/H relation is therefore sensitive to the sample of galaxies from which it is derived. This result casts doubt on the universal applicability of nitrogen-based strong-line metallicity indicators derived in the local universe.
