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arXiv 2603.01487astro-ph.GA
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LCEz4-M1: MUSE哈勃超深场中红移4.444的莱曼连续谱发射体候选体

LCEz4-M1: A Lyman Continuum Emitter Candidate at z = 4.444 in the MUSE Hubble Ultra Deep Field

Shanghai Astronomical Observatory, Chinese Academy of Sciences(中国科学院上海天文台);School of Astronomy and Space Sciences, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院);European Southern Observatory(欧洲南方天文台);Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS(中国科学院国家天文台拉美天文中心)

Shuairu Zhu, Zhen-Ya Zheng, Fuyan Bian, Fang-Ting Yuan, Chunyan Jiang, Xiaer Zhang, Ruqiu Lin, Yucheng Guo

AI总结:

基于VLT/MUSE和HST数据,报告一个红移4.444的莱曼连续谱发射体候选体LCEz4-M1,通过Lyα线确定红移,在F435W图像和MUSE光谱中独立探测到LyC信号,并推断出逃逸分数下限,结合JWST和MUSE数据表征其物理性质和形态。

摘要:

高红移莱曼连续谱发射体(LCEs)对于理解星系在再电离时代如何电离中性氢至关重要。然而,在$z>4$处探测到的LCEs相当罕见。这里我们报告一个红移$z=4.444$的LCE候选体,命名为LCEz4-M1,它是目前已知的最高红移LCE候选体之一。红移由VLT/MUSE光谱中探测到的Ly$α$发射线确定。莱曼连续谱(LyC)信号分别在 extit{哈勃空间望远镜}(HST)F435W图像和VLT/MUSE光谱中独立探测到,显著性分别为$\simeq3.7~σ$和$\simeq2.8-3.0~σ$。LyC质心与JWST/NIRCam连续谱在测量误差范围内空间一致。采用最大IGM透过率,我们推断出保守的下限逃逸分数$f_{ m esc}({ m F435W}) = 0.82^{+0.13}_{-0.17}$和$f_{ m esc}({ m MUSE}) = 0.75^{+0.18}_{-0.28}$。利用JWST和MUSE联合数据集,我们表征了LCEz4-M1的物理性质和形态。在我们仅使用JWST的基准SED拟合中,该星系致密但具有适中的当前星系整体恒星形成面密度$Σ_{ m SFR}=0.38~M_{\odot}\,{ m yr^{-1}\,kpc^{-2}}$,表明在此基准解释下它不是一个极端的致密星暴。虽然我们没有发现LCEz4-M1正在发生重大并合的明确证据,但在F277W波段探测到的一个暗弱伴星($\sim 0''5$)表明可能存在一次小型相互作用。我们还发现LCEz4-M1可能位于一个局部过密区域,尽管环境解释仍不确定。最后,LCEz4-M1的低${ m SFR}_{10\,{ m Myr}}/{ m SFR}_{100\,{ m Myr}}$比值、低Ly$α$等值宽度以及相对较弱的静止系光学发射线可能表明其处于爆发后LyC泄漏阶段。

英文摘要:

High-redshift Lyman continuum emitters (LCEs) are crucial for understanding how galaxies ionize the neutral hydrogen in the epoch of reionization. However, detected LCEs at $z>4$ are quite rare. Here we report an LCE candidate at $z = 4.444$, dubbed LCEz4-M1, which is one of the highest-redshift LCE candidates currently known. The redshift is determined from the Ly$α$ emission line detected in the VLT/MUSE spectrum. The Lyman continuum (LyC) signal is detected independently in the \emph{Hubble Space Telescope} (HST) F435W image and the VLT/MUSE spectrum at significances of $\simeq3.7~σ$ and $\simeq2.8-3.0~σ$, respectively. The LyC centroid is spatially consistent with the JWST/NIRCam continuum within the astrometric uncertainty. Adopting the maximum IGM transmission, we infer conservative lower-limit escape fractions of $f_{\rm esc}({\rm F435W}) = 0.82^{+0.13}_{-0.17}$ and $f_{\rm esc}({\rm MUSE}) = 0.75^{+0.18}_{-0.28}$. Using the combined JWST and MUSE data set, we characterize the physical properties and morphology of LCEz4-M1. In our fiducial JWST-only SED fit, the galaxy is compact but has a moderate current galaxy-integrated star formation surface density, $Σ_{\rm SFR}=0.38~M_{\odot}\,{\rm yr^{-1}\,kpc^{-2}}$, suggesting that it is not an extreme compact starburst under this fiducial interpretation. While we find no clear evidence for an ongoing major merger for LCEz4-M1, the presence of a faint companion ($\sim 0''5$) detected in the F277W band suggests a potential minor interaction. We also find that LCEz4-M1 may lie in a locally overdense region, although the environmental interpretation remains tentative. Finally, the low ${\rm SFR}_{10\,{\rm Myr}}/{\rm SFR}_{100\,{\rm Myr}}$ ratio, low Ly$α$ EW, and relatively weak rest-frame optical emission lines of LCEz4-M1 may indicate a post-burst LyC-leaking phase.

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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