论文标题
清除：星系1.1 <z <2.3的星系的电离和化学化特性
CLEAR: The Ionization and Chemical-Enrichment Properties of Galaxies at 1.1 < z < 2.3
论文作者
论文摘要
我们使用Hubble空间望远镜（HST）宽场相机3（WFC3）IR Grisms的深度光谱，结合了宽带光度计，以研究$ Z \ SIM \ SIM 1.1-2.3 $的星形星系中的恒星种群，气体电离和化学丰度。数据源于莱曼（Lyman）$ $α$在Revionization（Clear）调查中的排放。在这些红移时，grism光谱法测量了[OII] 3727，3729，[OIII] 4959，5008，H- $β$强排放特征，这限制了源含量的电离参数和氧气。我们将线路的测量与来自更新的光电离模型（映射（Kewley等人，2019年）的预测进行了比较，其中包括对烟丝气压的更新处理，log p / k = $ n_e t_e $。与低降差样本（$ z \ sim 0.2 $）相比，在固定的固定级别，llog m / m $ $ $ __ \ od. 4.4 Z = 1.35（Z = 1.90）具有较低的气相金属性，$δ$（log z）= 0.25（0.35）DEX和较高的电离参数，$δ$（log Q）= 0.25（0.25（0.35）dex，我们提供了U = Q/c之间的更新分析校准。金属性和电离参数。清晰的星系表明，在固定的恒星质量上，气体电离参数与星系特异性的恒星形成率（SSFRS）相关，其中$δ$ ug q = 0.4 $Δ$（log ssfr），来自$ $ $ $ eque persion的强度，分数与H-Iromatization光子的较高逃生部分相结合。
We use deep spectroscopy from the Hubble Space Telescope (HST) Wide-Field-Camera 3 (WFC3) IR grisms combined with broad-band photometry to study the stellar populations, gas ionization and chemical abundances in star-forming galaxies at $z\sim 1.1-2.3$. The data stem from the CANDELS Lyman-$α$ Emission At Reionization (CLEAR) survey. At these redshifts the grism spectroscopy measure the [OII] 3727, 3729, [OIII] 4959, 5008, H-$β$ strong emission features, which constrain the ionization parameter and oxygen abundance of the nebular gas. We compare the line flux measurements to predictions from updated photoionization models (MAPPINGS (Kewley et al. 2019), which include an updated treatment of nebular gas pressure, log P/k = $n_e T_e$. Compared to low-redshift samples ($z\sim 0.2$) at fixed stellar mass, llog M / M$_\odot$ = 9.4-9.8, the CLEAR galaxies at z=1.35 (z=1.90) have lower gas-phase metallicity, $Δ$(log Z) = 0.25 (0.35) dex, and higher ionization parameters, $Δ$(log q) = 0.25 (0.35) dex, where U = q/c. We provide updated analytic calibrations between the [OIII], [OII], and H-$β$ emission line ratios, metallicity, and ionization parameter. The CLEAR galaxies show that at fixed stellar mass, the gas ionization parameter is correlated with the galaxy specific star-formation rates (sSFRs), where $Δ$ log q = 0.4 $Δ$(log sSFR), derived from changes in the strength of galaxy H-$β$ equivalent width. We interpret this as a consequence of higher gas densities, lower gas covering fractions, combined with higher escape fraction of H-ionizing photons. We discuss both tests to confirm these assertions and implications this has for future observations of galaxies at higher redshifts.
