CLEAR: The Gas-phase Metallicity Gradients of Star-forming Galaxies at 0.6 < z < 2.6
CLEAR: The Gas-phase Metallicity Gradients of Star-forming Galaxies at 0.6 < z < 2.6
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DOI：
10.3847/1538-4357/ac28f4
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
R. Simons;C. Papovich;I. Momcheva;J. Trump;G. Brammer;V. Estrada-Carpenter;B. Backhaus;N. Cleri-N.-C
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文献类型：
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作者：
R. Simons;C. Papovich;I. Momcheva;J. Trump;G. Brammer;V. Estrada-Carpenter;B. Backhaus;N. Cleri-N.-C
我们报道了238个恒星形成星系样本的气相金属丰度梯度，这些星系的温度为0.6<；z<；2.6，用深近红外哈勃太空望远镜无缝隙光谱测量。观测包括作为CANDELS Lyα再电离发射(CLEAR)调查的一部分的12轨道深度哈勃/WFC3G102格栅光谱，以及与清晰足迹重叠的档案WFC3G102+G141格栅光谱。这个样本中的大多数星系在所探测的整个质量范围(8.5logM*/M≥<10.5)上都具有零或略为正的金属丰度梯度(DZ/DR⊙0，即随着半径的增加而增加)。我们测量了金属丰度梯度的本征布居散射，并表明它随着恒星质量的减少而增加-与文献中以前的报告一致，但这里用更大的样本证实了这一点。为了了解控制这种散射的物理机制，我们寻找在固定质量下观测到的梯度和各种恒星布居属性之间的关联。然而，我们没有发现与我们所考虑的星系属性相关的证据--包括恒星形成率、大小、恒星形成率、表面密度和每引力势能的恒星形成率。我们利用观察到的这些关联的弱点来为理论模型预测的内在关联提供物质约束。
We report on the gas-phase metallicity gradients of a sample of 238 star-forming galaxies at 0.6 < z < 2.6, measured through deep near-infrared Hubble Space Telescope slitless spectroscopy. The observations include 12 orbit depth Hubble/WFC3 G102 grism spectra taken as a part of the CANDELS Lyα Emission at Reionization (CLEAR) survey, and archival WFC3 G102+G141 grism spectra overlapping the CLEAR footprint. The majority of galaxies in this sample are consistent with having a zero or slightly positive metallicity gradient (dZ/dR ≥ 0, i.e., increasing with radius) across the full mass range probed (8.5 < log M */M ⊙ < 10.5). We measure the intrinsic population scatter of the metallicity gradients, and show that it increases with decreasing stellar mass—consistent with previous reports in the literature, but confirmed here with a much larger sample. To understand the physical mechanisms governing this scatter, we search for correlations between the observed gradient and various stellar population properties at fixed mass. However, we find no evidence for a correlation with the galaxy properties we consider—including star formation rates, sizes, star formation rate surface densities, and star formation rates per gravitational potential energy. We use the observed weakness of these correlations to provide material constraints for predicted intrinsic correlations from theoretical models.