arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.06255astro-ph.GA
收藏

连接高红移与低红移:我们是否正在用 JWST 观测银河系的前身?

Linking high-z and low-z: Are We Observing the Progenitors of the Milky Way with JWST?

Elka Rusta, Stefania Salvadori, Viola Gelli, Ioanna Koutsouridou, Alessandro Marconi

AI总结:

本文利用银河系演化模型 NEFERTITI 对 JWST 观测到的 Firefly Sparkle 进行前向建模,预测并识别银河系高红移前身,揭示其恒星形成历史与物理性质,从而连接高红移与低红移的银河系形成图景。

摘要:

JWST 最近对红移 z=8.3 处 Firefly Sparkle 的观测,为连接高红移与低红移宇宙提供了一个独特的机会。事实上,关于它是宇宙黎明时期银河系(MW)型组装体的说法,开启了利用本地校准的星系形成模型来解释该观测的可能性。在这里,我们使用银河系演化模型 NEFERTITI 对银河系在高红移处的前身进行前向建模。我们为银河系的构建块建立了一组模拟光谱,以便为 JWST 做出预测并解释 Firefly Sparkle 的观测。首先,我们发现质量最大的银河系前身在类似 JADES 的深度巡天中从 z≈8.2 开始变得可探测,这意味着我们可能已经观测到了仍需解释的银河系类似体。其次,我们为类似 CANUCS 的透镜巡天中可探测到的银河系前身数量提供了预测,并将 Firefly Sparkle 解释为一组银河系构建块。探测数量与观测到的 NIRCam 测光数据均与我们的预测一致。通过识别其模拟测光最符合数据的银河系前身,我们发现它们具有爆发式且延展的恒星形成历史,持续时间超过 150-300 Myr,并估计了它们的性质:M_h ≈ 10^{8-9} M_⊙,M_⋆ ≈ 10^{6.2-7.5} M_⊙,SFR ≈ 0.04-0.20 M_⊙ yr^{-1},Z_gas ≈ 0.04-0.24 Z_⊙。通过结合 JWST 观测和本地约束模型来揭示宇宙黎明时期银河系类似体的性质,将使我们能够理解银河系的形成,从而连接高红移与低红移的视角。

英文摘要:

The recent JWST observation of the Firefly Sparkle at $z=8.3$ offers a unique opportunity to link the high- and the low-$z$ Universe. Indeed, the claim of it being a Milky Way (MW) type of assembly at the cosmic dawn opens the possibility of interpreting the observation with locally calibrated galaxy-formation models. Here, we use the MW-evolution model NEFERTITI to perform forward modeling of our Galaxy's progenitors at high-$z$. We build a set of mock spectra for the MW building blocks to make predictions for JWST and to interpret the Firefly Sparkle observation. First, we find that the most massive MW progenitor becomes detectable in a deep survey like JADES from $z\approx 8.2$, meaning that we could have already observed MW-analogs that still need interpretation. Second, we provide predictions for the number of detectable MW progenitors in lensed surveys like CANUCS, and interpret the Firefly Sparkle as a group of MW building blocks. Both the number of detections and the observed NIRCam photometry are consistent with our predictions. By identifying the MW progenitors whose mock photometry best fits the data, we find bursty and extended star-formation histories, lasting $> 150-300$~Myr, and estimate their properties: $M_h \approx 10^{8-9} \, M_{\odot}$, $ M_\star \approx 10^{6.2-7.5}\, M_{\odot}$, $ SFR \approx 0.04-0.20 \, M_{\odot} yr^{-1}$ and $ Z_{gas} \approx 0.04 - 0.24 \, Z_{\odot}$. Uncovering the properties of MW-analogs at cosmic dawn by combining JWST observations and locally-constrained models, will allow us to understand our Galaxy's formation, linking the high- and low-$z$ perspectives.

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。

↑