高红移星系形成的ALMA视角
The ALMA View of High-Redshift Galaxy Formation
- Liverpool John Moores University（利物浦约翰摩尔斯大学）
- The University of Manchester（曼彻斯特大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本综述基于ALMA和NOEMA对z>6.5星系的观测，总结发现冷气体与恒星形成关系恒定、早期金属增丰、遮蔽比例趋势及尘埃快速增丰，并指出冷盘已存在且气体盘更延展。
AI中文摘要：
在过去的十年中，阿塔卡马大型毫米/亚毫米阵列（ALMA）进入常规运行，彻底改变了对静止系远红外（FIR）波段中“正常”高红移星系星际介质（ISM）的直接研究。本综述总结了使用ALMA和NOEMA（北方扩展毫米波阵列）观测z>6.5源的相关观测文献。主要发现如下：在广泛的星系环境中，冷气体与恒星形成持续成比例，与局域关系相似，这表明恒星形成的基本过程在130亿年的宇宙时间内保持相对恒定。在大爆炸后仅3-4亿年的星系中，已存在显著的金属增丰。在z~7时，已存在恒星形成被遮蔽比例随恒星质量和恒星形成率（SFR）增加的趋势，对宇宙恒星形成密度（SFR density）的测量表明，在该时期超过10%的恒星形成密度被遮蔽。与恒星质量相比，估算的尘埃质量表明尘埃快速增丰，可能来自超新星且尘埃破坏较少和/或在星际介质中快速生长，这与模型的最大预测一致。在单个源中，冷盘已经存在，其气体盘比观测到的恒星对应部分更延展且更平滑。
英文摘要：
The advent of routine operations with the Atacama Large Millimeter/submillimeter Array (ALMA) in the last decade has led to a revolution in the direct study of the interstellar medium (ISM) in `normal' high-redshift galaxies in the rest-frame far-infrared (FIR). This review summarizes the observational literature on z>6.5 sources observed with ALMA and NOEMA (NOrthern Extended Millimeter Array). The main findings are as follows: Cool gas consistently scales with star-formation in a wide range of galaxy environments, similar to local relations, suggesting fundamental processes of star-formation stay relatively constant over 13 billion years of cosmic time. Significant metal enrichment is present in galaxies just 300-400 million years after the Big Bang. There is a trend to higher obscured fraction of star formation with stellar mass and SFR already in place at z~7, with measurements of the cosmic SFR density showing that >10 percent of the SFR density is obscured at this epoch. The estimated dust masses compared to the stellar mass suggest that rapid dust enrichment occurs, likely from supernova with little dust destruction and/or rapid growth in the ISM, which is in agreement with maximal predictions from models. In individual sources cold disks are already in existence, with their gas disks being more extended and smooth than their observed stellar counterparts.
