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arXiv 2207.14733astro-ph.GA
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利用早期 JWST 数据揭示红外亮、光学暗星系的本质

Unveiling the Nature of Infrared Bright, Optically Dark Galaxies with Early JWST Data

L. Barrufet, P. A. Oesch, A. Weibel, G. Brammer, R. Bezanson, R. Bouwens, Y. Fudamoto, V. Gonzalez, R. Gottumukkala, G. Illingworth, K. E. Heintz, B. Holden, I.… 展开作者

L. Barrufet, P. A. Oesch, A. Weibel, G. Brammer, R. Bezanson, R. Bouwens, Y. Fudamoto, V. Gonzalez, R. Gottumukkala, G. Illingworth, K. E. Heintz, B. Holden, I. Labbe, D. Magee, R. P. Naidu, E. Nelson, M. Stefanon, R. Smit, P. van Dokkum, J. Weaver, C. Williams

AI总结:

本研究利用 JWST CEERS 项目的深场 NIRCam 成像,在 $z\sim2-8$ 识别出 30 个 HST-dark 大质量尘埃星系,发现其显著增加了宇宙普查中缺失的星系数量及 Reionization 纪元的恒星形成率密度。

摘要:

在过去几年中,ALMA 和 Spitzer/IRAC 的观测揭示了一群可能位于 $z>3$ 的大质量星系,它们在 HST 静止系紫外成像中太暗而无法被探测到。然而,由于单个星系的光度测量数据非常有限,这些所谓的 HST-dark 星系的真实性质仍然难以捉摸。在此,我们展示了由早期发布科学计划 CEERS 利用极深、高分辨率 NIRCam 成像观测到的首个此类星系样本。基于 1.6 $μ$m 到 4.4 $μ$m 之间的红色颜色,我们选出了 30 个 HST-dark 源。它们的物理性质由包含辅助 HST 成像在内的 12 波段多波长光度测量推导得出。我们发现这些星系通常是受尘埃严重遮挡($A_{V}\sim2$ mag)、大质量($\log (M/M_{\odot}) \sim10$)的恒星形成源,位于 $z\sim2-8$,观测面密度约为 $\sim0.8$ arcmin$^{-2}$。这表明在 $z>3$ 直至 Reionization 纪元,我们的宇宙普查中可能一直缺失了相当一部分大质量星系。这些 HST-dark 源位于星系主序上,并在 $z\sim7$ 处增加了 $\mathrm{3.2^{+1.8}_{-1.3} \times 10^{-3} M_{\odot}/yr/Mpc^{3}}$ 的受遮挡恒星形成率密度(SFRD),表明在 Reionization 纪元很可能存在尘埃。我们的分析表明,JWST 具有独特的能力来揭示这一此前缺失的星系群,并基于静止系光学成像提供 $z=2-8$ 更完整的星系普查。

英文摘要:

Over the last few years, both ALMA and Spitzer/IRAC observations have revealed a population of likely massive galaxies at $z>3$ that was too faint to be detected in HST rest-frame ultraviolet imaging. However, due to the very limited photometry for individual galaxies, the true nature of these so-called HST-dark galaxies has remained elusive. Here, we present the first sample of such galaxies observed with very deep, high-resolution NIRCam imaging from the Early Release Science Program CEERS. 30 HST-dark sources are selected based on their red colours across 1.6 $μ$m to 4.4 $μ$m. Their physical properties are derived from 12-band multi-wavelength photometry, including ancillary HST imaging. We find that these galaxies are generally heavily dust-obscured ($A_{V}\sim2$ mag), massive ($\log (M/M_{\odot}) \sim10$), star-forming sources at $z\sim2-8$ with an observed surface density of $\sim0.8$ arcmin$^{-2}$. This suggests that an important fraction of massive galaxies may have been missing from our cosmic census at $z>3$ all the way into the Reionization epoch. The HST-dark sources lie on the main sequence of galaxies and add an obscured star formation rate density (SFRD) of $\mathrm{3.2^{+1.8}_{-1.3} \times 10^{-3} M_{\odot}/yr/Mpc^{3}}$ at $z\sim7$ showing likely presence of dust in the Epoch of Reionization. Our analysis shows the unique power of JWST to reveal this previously missing galaxy population and to provide a more complete census of galaxies at $z=2-8$ based on rest-frame optical imaging.

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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