Portrait of the Galaxies in a Young Universe

年轻宇宙中星系的肖像

• 批准号: 0097163
• 负责人: Hyron Spinrad
• 金额: $ 27万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0097163&HistoricalAwards=false
• 关键词: Portrait; Galaxies; Young; Universe

ABSTRACT AST 0097163Spinrad How and when do galaxies form? Studies of the microwave background radiation show that the universe was spectacularly homogeneous at redshift of approximately 1000 (corresponding to ~ 3 x 10**5 years after the Big Bang). Locally, ~ 13 Gyr later, at time 0, we find that the distribution of matter is lumpy, with baryons largely consigned to luminous, bound structures. such as galaxies and clusters of galaxies. These present-day structures can be explained by the gravitational collapse and coalescence of the overdense regions of the early Universe. A detailed understanding of this collapse, called galaxy and large-scale structure formation, stands as one of the primary challenges to astrophysicists today.This project is a, three year systematic, observational study of the earliest phases of galaxy formation. It has three scientific objectives: (1) identifying galaxies at very high redshift (z 4). (2) characterizing the galaxy population(s) at early cosmic epoch. and (3) performing detailed physical studies on a subsample of these objects as a window toward understanding the early population(s) as a whole. To conduct this study, this project will significantly augment the census of very distant (z 4) galaxies using two proven techniques: (1) photometric selection of very high-redshift protogalaxy candidates from deep ground- and space-based imaging. and (2) slit spectroscopic searches for high-redshift line emission on deep exposures. Once these high redshift objects have been found they will be studied to find the cosmic star formation history at z 5, the prevalence of dust in the early Universe, the surface density and distribution of galaxies at early, cosmic time, and the luminosity function of both photometrically -selected and line-emitting galaxies in the early Universe. In particular. how are these two populations related? Studying both populations is essential for obtaining the truest understanding of the earliest phases of galaxy evolution. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***

摘要AST0097163自旋星系是如何以及何时形成的？对微波背景辐射的研究表明，宇宙在红移约为1000(相当于大爆炸后约3×10**5年)时是惊人的均匀。局部地，13Gyr以后，在时间0时，我们发现物质的分布是不均匀的，重子主要被委托给发光的束缚结构。比如星系和星系团。这些今天的结构可以用早期宇宙过密区域的引力坍塌和合并来解释。对这种被称为星系和大规模结构形成的崩塌的详细了解，是当今天体物理学家面临的主要挑战之一。这个项目是对星系形成的早期阶段进行的为期三年的系统观测研究。它有三个科学目标：(1)识别红移非常高的星系(Z4)。(2)描述早期宇宙纪元的星系群(S)。以及(3)对这些物体的一个亚样本进行详细的物理研究，以此作为了解早期人口(S)的一个窗口。为了进行这项研究，该项目将使用两种经过验证的技术显著增加对非常遥远的(Z4)星系的普查：(1)从深层地面和空间成像中以光度方法选择非常高红移的原星系候选星系。和(2)狭缝光谱寻找深曝光的高红移线发射。一旦这些高红移天体被发现，人们将对它们进行研究，以找到z5处的宇宙恒星形成历史，早期宇宙中尘埃的盛行，早期星系的表面密度和分布，以及早期宇宙中光度选择和线发射星系的光度函数。尤其是。这两个群体是如何相关的？研究这两个种群对于最真实地了解星系演化的最早阶段是至关重要的。该项目的资金由NSF河外天文与宇宙学计划(AST/EXC)提供。*