2023-11-13 ペンシルベニア州立大学(PennState)
◆ペンシルベニア州立大学の研究者を中心とする国際チームが、この古代の銀河の距離を確認し、JWSTの新しい分光データ（電磁スペクトル全体で放射される光に関する情報）を使用してそれらの特性を推測しました。約330億光年離れたこれらの極めて遠い銀河は、初期の銀河がどのように形成されたかについての洞察を提供します。
＜関連情報＞
- https://www.psu.edu/news/eberly-college-science/story/second-most-distant-galaxy-discovered-using-james-webb-space-telescope/
- https://iopscience.iop.org/article/10.3847/2041-8213/acfe07
UNCOVER: 初期宇宙を照らす-JWST/NIRSpecによるz > 12銀河の確認 UNCOVER: Illuminating the Early Universe—JWST/NIRSpec Confirmation of z > 12 Galaxies
Bingjie Wang (王冰洁), Seiji Fujimoto, Ivo Labbé, Lukas J. Furtak, Tim B. Miller, David J. Setton, Adi Zitrin, Hakim Atek, Rachel Bezanson, Gabriel Brammer, Joel Leja, Pascal A. Oesch, Sedona H. Price, Iryna Chemerynska, Sam E. Cutler, Pratika Dayal, Pieter van Dokkum, Andy D. Goulding, Jenny E. Greene, Y. Fudamoto, Gourav Khullar, Vasily Kokorev, Danilo Marchesini, Richard Pan, John R. Weaver, Katherine E. Whitaker, and Christina C. Williams
Astrophysical Journal Letters Published 2023 November 13
DOI:10.3847/2041-8213/acfe07
Abstract
Observations of high-redshift galaxies provide a critical direct test to the theories of early galaxy formation, yet to date, only three have been spectroscopically confirmed at z > 12. Due to strong gravitational lensing over a wide area, the galaxy cluster field A2744 is ideal for searching for the earliest galaxies. Here we present JWST/NIRSpec observations of two galaxies: a robust detection at Zspec=12.393+0.004−0.001, and a plausible candidate at Zspec=13.079+0.013−0.001. The galaxies are discovered in JWST/NIRCam imaging and their distances are inferred with JWST/NIRSpec spectroscopy, all from the JWST Cycle 1 UNCOVER Treasury survey. Detailed stellar population modeling using JWST NIRCam and NIRSpec data corroborates the primeval characteristics of these galaxies: low mass (∼108M⊙), young, rapidly assembling, metal-poor, and star-forming. Interestingly, both galaxies are spatially resolved, having lensing-corrected rest-UV effective radii on the order of 300–400 pc, which are notably larger than other spectroscopically confirmed systems at similar redshifts. The observed dynamic range of z ≳ 10 sizes spans over 1 order of magnitude, implying a significant scatter in the size–mass relation at early times. Deep into the epoch of reionization, these discoveries elucidate the emergence of the first galaxies.
