Evolution of Galaxies and Observational Cosmology

星系的演化和观测宇宙学

• 批准号: 02640207
• 负责人: YOSHII Yuzuru
• 金额: $ 1.54万
• 依托单位: National Astronomical Observatory
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640207/
• 关键词: Galaxy Evolution; Cosmology; Cosmological Constant

Cosmological predictions of number count and redshift distribution of faint galaxies are made by incorporating detection and selection effects in the theoretical framework. It is shown that the detection rate for galaxies at given apparent magnitude strongly depends on the detection criterion and magnitude measurement algorithm, and that a large number of faint galaxies with high redshifts should remain undetected in recent galaxy surveys. By using a current model of galaxy luminosity evolution with the assumption that galaxies do not evolve in number or cliameter, the predictions are compared directly with the uncorrected B_JR_FIK-band galaxy count data reaching B_J = 27mag or the equivalent depth and also with the Durham redshift distribution to B_J = 23mag. It is concluded that a flat and low-density OMEGA_O - 0.1 universe with non-zero cosmological constant can account for all the data but a flat and high-density OMEGA_O = 1 universe shows a marked discrepancy with all the data. The hypothesis of galaxy evolution in number and/or diameter is tested against the faint observations. Contrary to usual expectations, a number evolution driven by galaxy mergers cannot reconcile the observed high count at B_J = 27mag and the high densityOMEGA_O = 1 universe because many high-redshift premergers should not be counted according to the criterion adopted in the recent surveys. The central surface brightness versus apparent magnitude relation is found to be sensitive solely to a change of intrinsic size of galaxies so that it is used as a probe of their diameter evolution. Comparison between the predicted and observed relations indicates that the bulk of galaxies have undergone very little diameter evolution over a considerable fraction of their age.

在理论框架内结合探测和选择效应，对暗星系的计数和红移分布进行了宇宙学预言。结果表明，在给定的视星等星系的检测率强烈依赖于检测标准和星等测量算法，大量的高红移暗星系应保持在最近的星系巡天未被发现。在假设星系在数量和气候上都不演化的前提下，利用现有的星系光度演化模型，将预测结果与未校正的B_JR_FIK波段星系计数数据（B_J = 27等）和达勒姆红移分布（B_J = 23等）进行了比较。结果表明，一个平坦的低密度OMEGA_O - 0.1宇宙和非零宇宙学常数可以解释所有的数据，而一个平坦的高密度OMEGA_O = 1宇宙和所有的数据有显著的差异。星系演化的数量和/或直径的假设进行了测试对微弱的观测。与通常的预期相反，由星系合并驱动的数量演化不能使观测到的B_J = 27等的高计数和高密度OMEGA_O = 1的宇宙相一致，因为许多高红移的预合并不应该按照最近的调查所采用的标准来计算。中心表面亮度与视星等的关系被发现是敏感的唯一的变化的固有大小的星系，使它被用作探针的直径演化。预测和观察到的关系之间的比较表明，大部分的星系经历了非常小的直径演变在相当一部分的年龄。

项目成果

吉井 讓: "Constraints on the Universe with Decaying Cosmological Constant from Number Count of Faint Galaxies" Astrophys.J.Letters. 387. 7-11 (1992)

Yu Yoshii：“来自微弱星系数量的衰变宇宙学常数对宇宙的约束”Astrophys.J.Letters 387. 7-11 (1992)

有本 信雄: "Luminosity Evolution of Disk Galaxies" Astron.Astrophys.253. 21-34 (1992)

有本伸夫：“盘状星系的光度演化”Astron.Astrophys.253（1992）。

Y. Yoshii: "Observational Constraints on OMEGA_O and LAMBDA" Genshikaku Kenkyu. 35. 1-17 (1990)

Y. Yoshii：“OMEGA_O 和 LAMBDA 的观测约束”Genshikaku Kenkyu。

吉井 讓: "Faint Galaxies:Bounds on the Epoch of Galaxy Formation and Cosmological Deceleration Parameter" Astrophys.J.372. 8-20 (1991)

Yoshii Yoshi：“微弱星系：星系形成时代和宇宙学减速参数的界限”Astrophys.J.372（1991）。

Y. Yoshii: "Colour Change of Galaxies with Star-Forming Activities" Astron. Astrophys.248. 30-36 (1991)

Y. Yoshii：“恒星形成活动导致的星系颜色变化”Astron。