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arXiv 2405.09354astro-ph.GA
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3D-DASH:0.5 < z < 3 范围内年轻与年老宁静星系族群的大小、形状及内禀弥散的演化

3D-DASH: The Evolution of Size, Shape, and Intrinsic Scatter in Populations of Young and Old Quiescent Galaxies at 0.5 < z < 3

Maike Clausen, Katherine E. Whitaker, Ivelina Momcheva, Sam E. Cutler, Katherine A. Suess, John R. Weaver, Tim Miller, Arjen van der Wel, Stijn Wuyts, David Wak… 展开作者

Maike Clausen, Katherine E. Whitaker, Ivelina Momcheva, Sam E. Cutler, Katherine A. Suess, John R. Weaver, Tim Miller, Arjen van der Wel, Stijn Wuyts, David Wake, Pieter van Dokkum, Rachel S. Bezanson, Gabriel Brammer, Marijn Franx, Erica J. Nelson, Natasha M. Foerster Schreiber

AI总结:

本研究利用3D-DASH巡天与COSMOS2020星表数据,探究0.5<z<3区间年轻与年老宁静星系的结构演化,发现尺寸差异由大质量子族群主导,两类星系尺寸内禀弥散在z~2达峰,高红移停止恒星形成的星系更致密,低红移则有多种演化路径。

摘要:

我们通过追踪4518个年老宁静星系与583个年轻宁静星系样本的数密度及结构演化,开展了0.5 < z < 3区间内宁静星系族群增长的研究,样本恒星质量满足log($M_*$/$M_{\u2299}$)>10.4,选自COSMOS2020星表,并搭配来自3D-DASH巡天的HST/F160W成像数据作为补充。在红移z~2的宁静星系族群中,约50%是近期被 quenched(停止恒星形成)的星系;这类年轻宁静星系在红移更低时数量愈发稀少,支持了大质量星系的恒星形成停止峰值期出现在z>2的观点。我们的数据显示,尽管宁静星系的有效半光半径总体随时间增大,但在同一红移下,年轻宁静星系的尺寸显著小于年老宁静星系。本工作中我们探究了这种尺寸差异与其他结构属性的关联,包括轴比、颜色梯度、恒星质量,以及有效半径的内禀弥散。我们证实,该尺寸差异由质量最高的子族群(log($M_*$/$M_{\u2299}$)>11)主导,当将样本限定为中等质量星系(10.4<log($M_*$/$M_{\u2299}$)<11)时,这种差异不再存在。有趣的是,在研究的时间范围内,物理尺寸的内禀弥散呈现出强烈的共同演化特征,两类族群的弥散都在z~2附近达到峰值,仅在z < 1时出现分化。综上,在我们没有遗漏大量低表面亮度星系的前提下,高红移时期占主导的星系形成与恒星形成停止机制会产生致密的残留天体,而多种演化路径可以解释在z<1时停止恒星形成的星系的多样形态。

英文摘要:

We present a study of the growth of the quiescent galaxy population between 0.5 < z < 3 by tracing the number density and structural evolution of a sample of 4518 old and 583 young quiescent galaxies with log($M_*$/$M_{\odot}$)>10.4, selected from the COSMOS2020 catalog with complementary HST/F160W imaging from the 3D-DASH survey. Among the quiescent population at z$\sim$2, roughly 50% are recently quenched galaxies; these young quiescent galaxies become increasingly rare towards lower redshift, supporting the idea that the peak epoch of massive galaxy quenching occurred at z>2. Our data show that while the effective half-light radii of quiescent galaxies generally increases with time, young quiescent galaxies are significantly smaller than their older counterparts at the same redshift. In this work we investigate the connection between this size difference and other structural properties, including axis ratios, color gradients, stellar mass, and the intrinsic scatter in effective radii. We demonstrate that the size difference is driven by the most massive sub-population (log($M_*$/$M_{\odot}$)>11) and does not persist when restricting the sample to intermediate mass galaxies (10.4<log($M_*$/$M_{\odot}$)<11). Interestingly, the intrinsic scatter in physical size shows a strong co-evolution over the investigated time period and peaks around z$\sim$2 for both populations, only diverging at z < 1. Taken together, and assuming we are not missing a significant population of lower surface brightness galaxies, while the formation and quenching mechanisms that dominate at higher redshifts yield compact remnants, multiple evolutionary pathways may explain the diverse morphologies of galaxies that quench at z<1.

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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