再电离纪元的多相星系周介质：[OIII]发射体周围的CII和CIV吸收体
The Multiphase CGM in the Epoch of Reionization: CII and CIV absorbers around [OIII] Emitters
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中文总结 AI 辅助
通过JWST和地面望远镜数据，互相关分析发现再电离纪元星系周围CII和CIV吸收体过量，且暖电离相更延展，碳金属已扩散至星系周介质之外。
中文摘要 AI 辅助
我们通过将冷CII和暖电离CIV吸收系统与恒星形成的[OIII]发射体进行互相关，研究了再电离纪元（EoR，$z>6$）期间的多相星系周介质（CGM）。来自EIGER巡天的JWST/NIRCam宽场无缝光谱与六个背景类星体的中、高分辨率光学/近红外光谱相结合，其中包括对PSO J159-02的新VLT/X-Shooter观测。我们分析了16个CII和14个CIV吸收体（$\log(N) > 13.0$）与136个星系之间的关系，碰撞参数R$_{\perp} \leq$ 1000 pkpc，视线方向分离$\Delta v \leq 500$ km/s。与随机背景相比，我们检测到星系周围这两种离子均存在统计显著的过量。我们观察到CIV覆盖分数在$\sim 1$ pMpc范围内保持增强，而CII在$\sim 0.5$ pMpc之外降至背景水平，表明暖电离相在空间上比冷气体更延展。联合来看，三维星系-吸收体空间聚集显著弱于星系-星系自相关。这提供了直接的物理证据，表明早期碳增丰并不局限于大质量恒星形成系统的维里半径内；相反，这些金属的相当一部分渗透到弥散星系间介质（IGM）中，或由广泛分布的微弱、未探测到的矮星系注入。最后，我们注意到与$z<2$和$z\sim3-4$的低红移样本相比，CIV覆盖分数快速径向下降，表明CGM电离结构在演化，早期金属主要存在于较低电离态。总之，我们确定了在300 pkpc内观测到的碳质量$\rm M_{CII + CIV} \geq 2.8 \times 10^6 \\\\, M_{\odot}$的保守下限。
英文摘要
We investigate the multiphase circumgalactic medium (CGM) during the Epoch of Reionization (EoR, $z>6$) by cross-correlating cool- CII and warm-ionized CIV absorption systems with star-forming [OIII] emitters. JWST/NIRCam wide-field slitless spectroscopy from the EIGER survey is combined with medium- and high-resolution optical/NIR spectra of six background quasars, including new VLT/X-Shooter observations of PSO J159-02. We analyze the relation between 16 CII and 14 CIV absorbers ($\log(N) > 13.0$) and 136 galaxies, within an impact parameter of R$_{\perp} \leq$ 1000 pkpc and a line-of-sight separation of $Δv \leq 500$ km/s. We detect a statistically significant excess of both ions around galaxies compared to a randomized background. We observe that the CIV covering fraction remains enhanced up to $\sim 1$ pMpc, whereas CII drops to the background level beyond $\sim 0.5$ pMpc, demonstrating that the warm-ionized phase is more spatially extended than cooler gas. Jointly, the 3D galaxy-absorber spatial clustering is significantly weaker than the galaxy-galaxy auto-correlation. This provides direct physical evidence that early carbon enrichment is not confined to the virial radius of massive star-forming systems; rather, a substantial fraction of these metals permeates the diffuse intergalactic medium (IGM) or is injected by a widespread population of faint, undetected dwarf galaxies. Finally, we note a rapid radial decline of the CIV covering fraction compared with lower redshift samples at $z<2$ and $z\sim3-4$ pointing out an evolving CGM ionization structure where early metals reside predominantly in lower ionization states. In conclusion, we determine a conservative lower limit for the observed carbon mass of $\rm M_{CII + CIV} \geq 2.8 \times 10^6 \, M_{\odot}$ within 300 pkpc.
发表机构
- University of Trieste（的里雅斯特大学）
- INAF - Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）
- IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）
- Dipartimento di Fisica “Enrico Fermi”, Università di Pisa（比萨大学恩里科·费米物理系）
- IUCAA（印度联合大学天体物理中心）
- Università degli Studi di Milano-Bicocca（米兰比可卡大学）
- Max-Planck-Institut für Ex
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