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arXiv 2406.11571astro-ph.GA
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PRIMER:JWST/MIRI揭示z<2.5星系中恒星形成结构的演化

PRIMER: JWST/MIRI reveals the evolution of star-forming structures in galaxies at z<2.5

Yipeng Lyu, Benjamin Magnelli, David Elbaz, Pablo G. Pérez-González, Camila Correa, Emanuele Daddi, Carlos Gómez-Guijarro, James S. Dunlop, Norman A. Grogin, An… 展开作者

Yipeng Lyu, Benjamin Magnelli, David Elbaz, Pablo G. Pérez-González, Camila Correa, Emanuele Daddi, Carlos Gómez-Guijarro, James S. Dunlop, Norman A. Grogin, Anton M. Koekemoer, Derek J. McLeod, Shiying Lu

AI总结:

本研究利用JWST/MIRI观测分析了665个z<2.5星系,揭示了恒星形成星系结构演化主要由由内向外增长主导,但会被可原位构建致密核球的剧烈致密化阶段打断。

摘要:

恒星形成星系(SFGs)的恒星结构在其质量组装过程中经历显著的尺寸增长,并且在演化为宁静星系(QGs)时必须经历一个致密化阶段。为了阐明这种结构演化背后的机制,我们利用JWST/MIRI观测研究了665个处于0<z<2.5的SFGs的恒星形成组分的形态,并将它们与文献中其恒星组分的形态进行了比较。大多数SFGs(66%)的恒星和恒星形成组分具有延展的盘状结构,这些结构彼此对齐且尺寸相同。这些星系的恒星形成组分遵循质量-尺寸关系,与其恒星组分遵循的关系类似。在最高质量处,这些SFGs的光学Sérsic指数增加至2.5,表明存在主导性的恒星核球。由于它们的恒星形成组分保持盘状,这些核球不可能由自发的原位增长形成。我们识别出位于MIR质量-尺寸关系之下的第二类星系群,其致密的恒星形成组分嵌在延展的恒星组分中(EC星系)。这些星系总体上很罕见(15%),但在高质量($>10^{10.5}M_\odot$)处变得更为主导(30%)。这些星系致密的恒星形成组分同样集中且略呈球状,表明这一致密化阶段可以原位构建致密核球。最后,我们识别出第三类SFGs(19%),其恒星和恒星形成组分均致密。它们恒星核心的密度与QGs相似,符合作为EC星系后代的特征。总体而言,SFGs的结构演化主要由自发的由内向外增长主导,但这可能会被剧烈的致密化阶段打断,后者能够构建出如大质量SFGs或QGs中那样的主导性恒星核球。

英文摘要:

The stellar structures of star-forming galaxies (SFGs) undergo significant size growth during their mass assembly and must pass through a compaction phase as they evolve into quiescent galaxies (QGs). To shed light on the mechanisms behind this structural evolution, we study the morphology of the star-forming components of 665 SFGs at 0<z<2.5 measured using JWST/MIRI observation and compare them with the morphology of their stellar components taken from the literature. The stellar and star-forming components of most SFGs (66%) have extended disk-like structures that are aligned with each other and are of the same size. The star-forming components of these galaxies follow a mass-size relation, similar to that followed by their stellar components. At the highest mass, the optical Sérsic index of these SFGs increases to 2.5, suggesting the presence of a dominant stellar bulge. Because their star-forming components remain disk-like, these bulges cannot have formed by secular in-situ growth. We identify a second population of galaxies lying below the MIR mass-size relation, with compact star-forming components embedded in extended stellar components (EC galaxy). These galaxies are overall rare (15%) but become more dominant (30%) at high mass ($>10^{10.5}M_\odot$). The compact star-forming components of these galaxies are also concentrated and slightly spheroidal, suggesting that this compaction phase can build dense bulge in-situ. Finally, we identify a third population of SFGs (19%), with both compact stellar and star-forming components. The density of their stellar cores resemble those of QGs and are compatible with being the descendants of EC galaxy. Overall, the structural evolution of SFGs is mainly dominated by a secular inside-out growth, which can, however, be interrupted by violent compaction phase(s) that can build dominant stellar bulges like those in massive SFGs or QGs.

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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