论文标题
MOSDEF调查：霓虹灯是高红移时ISM物理条件的探针
The MOSDEF Survey: Neon as a Probe of ISM Physical Conditions at High Redshift
论文作者
论文摘要
我们介绍了从Mosfire深层进化场（MOSDEF）调查中绘制的$ z \ sim2 $星形星系中霓虹灯排放的性质的结果。在61个星系中以$ \geq3σ$检测到双离子化的霓虹灯（[Neiii] 3869），代表$ \ sim $ \ sim $ 25％的Mosdef样品，带有H $α$，H $β$，[OIIII] $ 5007 $ 5007 $在类似的redshifts上检测。我们考虑了两个单个星系的霓虹灯发射线特性，具有[NEIII] 3869检测和由Stellar Mass键入的复合$ Z \ SIM2 $ SPECTRA。不需要[NEIII] 3869检测，后者提供了MOSDEF样品中霓虹灯发射线特性的更具代表性的图片。 [NEIII] 3869/[OII] 3727比率（NE3O2）与$ z \ sim2 $星系中的恒星质量抗相关，这是基于质量金属关系的预期。它也与[OIII] $ 5007 $/[OII] $ 3727 $比率（O32）呈正相关，但是与本地恒星形成的星系和单个H〜II区相比，$ Z \ SIM2 $线路比在固定的O32处取代了更高的Ne3O2。尽管在$ z \ sim2 $下以固定的O32处降低了NE3O2的偏移，但基于NE3O2的基于NE3O2的金属性的偏见很小。因此，NE3O2可以用作深入电离时期的重要金属性指标。 Analyzing additional rest-optical line ratios including [NeIII]$3869$/[OIII]$5007$ (Ne3O3) and [OIII]$5007$/H$β$ (O3H$β$), we conclude that the nebular emission-line ratios of $z\sim2$ star-forming galaxies suggest a harder ionizing spectrum (lower stellar与$ z \ sim0 $的系统相比，在固定的气相氧气中，金属性，即Fe/h）。这些新的结果基于对高降射星形星系中的电离ISM的氧，氮，氢和硫发射的物理图片的支持，这些结果被化学幼年的高红色恒星形成星系辐照，$α$ a $α$ a $ a $ a $ a $ a $增强的巨星。
We present results on the properties of neon emission in $z\sim2$ star-forming galaxies drawn from the MOSFIRE Deep Evolution Field (MOSDEF) survey. Doubly-ionized neon ([NeIII]3869) is detected at $\geq3σ$ in 61 galaxies, representing $\sim$25% of the MOSDEF sample with H$α$, H$β$, and [OIII]$5007$ detections at similar redshifts. We consider the neon emission-line properties of both individual galaxies with [NeIII]3869 detections and composite $z\sim2$ spectra binned by stellar mass. With no requirement of [NeIII]3869 detection, the latter provide a more representative picture of neon emission-line properties in the MOSDEF sample. The [NeIII]3869/[OII]3727 ratio (Ne3O2) is anti-correlated with stellar mass in $z\sim2$ galaxies, as expected based on the mass-metallicity relation. It is also positively correlated with the [OIII]$5007$/[OII]$3727$ ratio (O32), but $z\sim2$ line ratios are offset towards higher Ne3O2 at fixed O32, compared with both local star-forming galaxies and individual H~II regions. Despite the offset towards higher Ne3O2 at fixed O32 at $z\sim2$, biases in inferred Ne3O2-based metallicity are small. Accordingly, Ne3O2 may serve as an important metallicity indicator deep into the reionization epoch. Analyzing additional rest-optical line ratios including [NeIII]$3869$/[OIII]$5007$ (Ne3O3) and [OIII]$5007$/H$β$ (O3H$β$), we conclude that the nebular emission-line ratios of $z\sim2$ star-forming galaxies suggest a harder ionizing spectrum (lower stellar metallicity, i.e., Fe/H) at fixed gas-phase oxygen abundance, compared to systems at $z\sim0$. These new results based on neon lend support to the physical picture painted by oxygen, nitrogen, hydrogen, and sulfur emission, of an ionized ISM in high-redshift star-forming galaxies irradiated by chemically young, $α$-enhanced massive stars.
