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arXiv 2305.02478astro-ph.GAastro-ph.CO
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通过JWST的视角看红移$z\rsim6$处的星系形态

Galaxy Morphology from $z\sim6$ through the eyes of JWST

M. Huertas-Company, K. G. Iyer, E. Angeloudi, M. B. Bagley, S. L. Finkelstein, J. Kartaltepe, R. Sarmiento, J. Vega-Ferrero, P. Arrabal Haro, P. Behroozi, F. Bu… 展开作者

M. Huertas-Company, K. G. Iyer, E. Angeloudi, M. B. Bagley, S. L. Finkelstein, J. Kartaltepe, R. Sarmiento, J. Vega-Ferrero, P. Arrabal Haro, P. Behroozi, F. Buitrago, Y. Cheng, L. Costantin, A. Dekel, M. Dickinson, D. Elbaz, N. A. Grogin, N. P. Hathi, B. W. Holwerda, A. M. Koekemoer, R. A. Lucas, C. Papovich, P. G. Pérez-González, N. Pirzkal, L-M. Seillé, A. de la Vega, S. Wuyts, G. Yang, L. Y. A. Yung

AI总结:

本研究利用JWST数据分析了0<z<6范围内大质量星系的近红外静止形态,发布含约20000个星系的CEERS巡天形态星表,证实早期宇宙星系形态多样性丰富,且z>3时大质量星系的形态与恒星形成熄灭已存在关联。

摘要:

我们分析了红移范围$0<z<6$内、恒星质量满足$\rsim M_*/M_\rsim>9$的星系的近红外($\rsim0.8-1\rsim$m)静止坐标系形态,将其与此前基于哈勃空间望远镜(HST)的研究结果进行对比,并发布了CEERS巡天中首个基于詹姆斯·韦布空间望远镜(JWST)的、包含约20000个星系的形态星表。我们利用$F150W$、$F200W$、$F356W$和$F444W$四个滤光片的成像数据,采用在HST/WFC3标记图像上训练、并经域适应适配到JWST/NIRCam的卷积神经网络,将星系分为四大类:椭球星系、盘+椭球星系、盘星系和扰动星系。我们发现,在考虑相近波长的情况下,$z<3$处约90%的星系在JWST和HST成像中的早型/晚型分类一致,约75%的星系的规则/不规则分类一致。对于小(大)且暗弱的天体,基于JWST的分类往往系统性地呈现出比基于HST的分类更少的核球主导系统(特殊星系),但这一差异对已报道的形态占比演化的影响小于约10%。利用基于JWST的、在相同静止波长($\rsim0.8-1\rsim$m)下的形态测量结果,我们证实了此前基于HST的研究报道的现象:随着红移升高,特殊星系占比增加,核球主导星系占比减少,这表明早期宇宙中除了光分布,恒星质量分布也更具扰动性。然而我们发现,在$z\rsim5$时,未受扰动的盘状系统已经在晚型星系的大质量端($\rsim M_*/M_\rsim>10.5$)占据主导,且核球主导星系在这些早期时期也已存在,证实了大爆炸后约10亿年的星系已经具备丰富且演化程度较高的形态多样性。最后我们发现,对于$z>3$的大质量星系,形态与恒星形成熄灭的关联已经建立,大质量宁静星系($\rsim M_*/M_\rsim>10.5$)以核球主导为主。

英文摘要:

We analyze the Near Infrared ($\sim0.8-1μ$m) rest-frame morphologies of galaxies with $\log M_*/M_\odot>9$ in the redshift range $0<z<6$, compare with previous HST-based results and release the first JWST-based morphological catalog of $\sim20,000$ galaxies in the CEERS survey. Galaxies are classified into four main broad classes -- spheroid, disk+spheroid, disk, and disturbed -- based on imaging with four filters -- $F150W$, $F200W$, $F356W$, and $F444W$ -- using Convolutional Neural Networks trained on HST/WFC3 labeled images and domain-adapted to JWST/NIRCam. We find that $\sim90\%$ and $\sim75\%$ of galaxies at $z<3$ have the same early/late and regular/irregular classification, respectively, in JWST and HST imaging when considering similar wavelengths. For small (large) and faint objects, JWST-based classifications tend to systematically present less bulge-dominated systems (peculiar galaxies) than HST-based ones, but the impact on the reported evolution of morphological fractions is less than $\sim10\%$. Using JWST-based morphologies at the same rest-frame wavelength ($\sim0.8-1μ$m), we confirm an increase in peculiar galaxies and a decrease in bulge-dominated galaxies with redshift, as reported in previous HST-based works, suggesting that the stellar mass distribution, in addition to light distribution, is more disturbed in the early universe. However, we find that undisturbed disk-like systems already dominate the high-mass end of the late-type galaxy population ($\log M_*/M_\odot>10.5$) at $z\sim5$, and bulge-dominated galaxies also exist at these early epochs, confirming a rich and evolved morphological diversity of galaxies $\sim1$ Gyr after the Big Bang. Finally, we find that the morphology-quenching relation is already in place for massive galaxies at $z>3$, with massive quiescent galaxies ($\log M_*/M_\odot>10.5$) being predominantly bulge-dominated.

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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