Galaxies at Redshifts z~2: The Apex of Galaxy Formation

该项目的首席研究员和合作者将结合三种复杂的计算机代码，以模拟大约20（大约100亿年前）红移时星系的特性。这些代码是：(1)基于Voronoi细分的非结构化自适应网格流体力学代码Arepo；(2) Sunrise，一个蒙特卡罗辐射传输代码，计算由散射和吸收调制的恒星和非热源星系从紫外到毫米波的光谱能量分布；(3) Turtlebeach，一个类似的辐射传输代码，可以计算分子光谱线发射。该团队将使用这些耦合代码创建一个孤立的、演化的和合并的星系的流体动力学模拟库。然后，他们将通过半解析和数值方法获得的宇宙合并率和合并历史的估计来折叠所得模型。这一策略将使在几十秒差距尺度上运行的物理机制与大规模星系调查的观测结果联系起来成为可能。该项目的目标是：(1)为高红移星系的多样性“动物园”构建一个物理动机的统一模型，包括预计将在阿塔卡马大型毫米波阵列、詹姆斯韦伯太空望远镜和赫歇尔太空望远镜的深入调查中发现的星系群；(2)评估各种高红移星系群的宇宙学意义，确定宇宙恒星质量集合和远红外背景的主要贡献者；(3)基于对高红移星系的物理理解和对局部校准诊断适用性的关键评估，为观测者开发工具。该项目将资助一名博士后研究员和一名研究生，由首席研究员指导和培训。在这些调查之前，提议者将公开ALMA、JWST和赫歇尔深场的社区期望光度函数。他们还将举办一系列1小时的讲座，作为老年人继续教育计划的一部分。

The Principal Investigator and collaborators in this project will combine three sophisticated computer codes in order to simulate the properties of galaxies at redshifts around 2 (approximately 10 billion years ago). These codes are (1) Arepo, an unstructured-adaptive-mesh hydrodynamics code based on Voronoi tessellations; (2) Sunrise, a Monte Carlo radiative transfer code that calculates spectral energy distributions from ultraviolet to millimeter wavelengths for galaxies with stellar and nonthermal sources modulated by scattering and absorption; and (3) Turtlebeach, a similar radiative transfer code that calculates molecular spectral line emission. The team will use these coupled codes to create a library of hydrodynamic simulations of isolated, evolving, and merging galaxies. They will then fold the resulting models through estimates of cosmological merger rates and merging histories obtained through semi-analytic and numerical methods. This strategy will make it possible to connect physical mechanisms operating on scales of tens of parsecs to observations from large-scale galaxy surveys. The goals of the project are (1) to construct a physically motivated unified model for the diverse "zoo" of high redshift galaxies, including galaxy populations expected to be discovered in deep surveys by the Atacama Large Millimeter Array, the James Webb Space Telescope, and the Herschel Space Telescope; (2) to assess the cosmological significance of the various high redshift galaxy populations, and determine the dominant contributors to cosmic stellar mass assembly and the far infrared background; and (3) to develop tools for observers based on a physical understanding of high-redshift galaxies and a critical assessment of the applicability of locally-calibrated diagnostics. The project will support a postdoctoral researcher and a graduate student, who will be mentored and trained by the Principal Investigator. The proposers will make public for the community expected luminosity functions for ALMA, JWST and Herschel deep fields in advance of these surveys. They will also conduct a series of 1-hour lectures as part of a continuing education program for senior citizens.