The first wave of observations with JWST has revealed a striking overabundance of luminous galaxies at early times (z > 10) compared to models of galaxies calibrated to pre-JWST data. Early observations have also uncovered a large population of supermassive black holes (SMBHs) at z > 6. Because many of the high-z objects appear extended, the contribution of active galactic nuclei (AGNs) to the total luminosity has been assumed to be negligible. In this work, we use a semi-empirical model for assigning AGNs to galaxies to show that active galaxies can boost the stellar luminosity function (LF) enough to solve the overabundance problem while simultaneously remaining consistent with the observed morphologies of high-z sources. We construct a model for the composite AGN+galaxy LF by connecting dark matter halo masses to galaxy and SMBH masses and luminosities, accounting for dispersion in the mapping between host galaxy and SMBH mass and luminosity. By calibrating the model parameters — which characterize the M _∙ -M_* relation — to a compilation of z > 10 JWST UVLF data, we show that AGN emission can account for the excess luminosity under a variety of scenarios, including one where 10% of galaxies host BHs of comparable luminosities to their stellar components. Using a sample of simulated objects and real observations, we demonstrate that such low-luminosity AGNs can be `hidden' in their host galaxies and be missed in common morphological analyses. We find that for this explanation to be viable, our model requires a population of BHs that are overmassive (M _∙ /M_* ~ 10^-2) with respect to their host galaxies compared to the local relation and are more consistent with the observed relation at z = 4-8. We explore the implications of this model for BH seed properties and comment on observational diagnostics necessary to further investigate this explanation.

中文翻译：

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隐藏的活跃星系核群体可以解释 JWST 观测到的发光 z > 10 物体的过多现象


詹姆斯韦伯太空望远镜的第一波观测揭示了早期发光星系数量惊人的过多（ z > 10) 与根据 JWST 数据校准之前的星系模型进行比较。早期观测还发现了大量的超大质量黑洞（SMBH） z > 6. 因为许多高z当物体看起来很延伸时，活动星系核（AGN）对总光度的贡献被认为可以忽略不计。在这项工作中，我们使用半经验模型将活动星系核分配给星系，以表明活跃星系可以增强恒星光度函数（LF），足以解决过剩问题，同时与观测到的高恒星形态保持一致。 z来源。我们通过将暗物质晕质量与星系和SMBH质量和光度连接起来，构建了一个复合AGN+星系LF模型，解释了宿主星系与SMBH质量和光度之间映射的色散。通过校准模型参数——表征 M _∙ -M _*关系 — 到一个汇编z > 10 JWST UVLF 数据，我们表明 AGN 发射可以解释各种情况下的过量光度，包括 10% 的星系拥有与其恒星成分光度相当的 BH 的情况。使用模拟物体样本和真实观测结果，我们证明了这种低光度活动星系核可以“隐藏”在它们的宿主星系中，并且在常见的形态分析中被遗漏。 我们发现，为了使这种解释可行，我们的模型需要大量 BH（M _∙ /M _* ~ 10 ^-2 ) 相对于它们的宿主星系与本地关系相比，并且与观测到的关系更一致z = 4-8。我们探讨了该模型对 BH 种子特性的影响，并对进一步研究这一解释所需的观察诊断进行了评论。