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arXiv 1910.09730astro-ph.GA
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通过发射线了解星系演化

Understanding Galaxy Evolution through Emission Lines

Lisa J. Kewley, David C. Nicholls, Ralph S. Sutherland

摘要:

本文从激发源、金属丰度、电离参数、ISM压力和电子密度等方面综述了发射线在星系演化研究中的应用。我们表明,紫外线,光学和红外包含互补的诊断,可以探测不同的星云电离区内的条件。在即将到来的望远镜设施的预期,我们提供了新的自我一致的发射线诊断校准完整的光谱覆盖范围从紫外到红外。这些诊断可以协同使用,以了解星系的基本属性如何在宇宙时间内发生变化。我们描述了新的二维和三维发射线诊断分离的贡献,恒星形成,活动星系核和冲击,使用积分场光谱。我们讨论的物理,好处,和警告的发射线诊断,包括理论模型的不确定性,扩散电离气体的影响,和样品选择的偏见。占复杂的密度梯度和温度分布是至关重要的可靠估计H II区域和星系的基本属性。扩散电离气体可以提高金属丰度的估计值,使金属丰度梯度变平,并在电离参数测量中引入散射。我们总结了未来几年排放线诊断的挑战和主要机遇。

英文摘要:

We review the use of emission-lines for understanding galaxy evolution, focusing on excitation source, metallicity, ionization parameter, ISM pressure and electron density. We show that the UV, optical and infrared contain complementary diagnostics that can probe the conditions within different nebular ionization zones. In anticipation of upcoming telescope facilities, we provide new self-consistent emission-line diagnostic calibrations for complete spectral coverage from the UV to the infrared. These diagnostics can be used in concert to understand how fundamental galaxy properties have changed across cosmic time. We describe new 2D and 3D emission-line diagnostics to separate the contributions from star formation, AGN and shocks using integral field spectroscopy. We discuss the physics, benefits, and caveats of emission-line diagnostics, including the effect of theoretical model uncertainties, diffuse ionized gas, and sample selection bias. Accounting for complex density gradients and temperature profiles is critical for reliably estimating the fundamental properties of H ii regions and galaxies. Diffuse ionized gas can raise metallicity estimates, flatten metallicity gradients, and introduce scatter in ionization parameter measurements. We summarize with a discussion of the challenges and major opportunities for emission-line diagnostics in the coming years.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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