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arXiv 2301.09614astro-ph.COastro-ph.GAhep-ex
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z>11星系候选体中的点状源:高红移超新星造成的污染?

Point-like sources among z>11 galaxy candidates: contaminants due to supernovae at high redshifts?

Haojing Yan, Lifan Wang, Zhiyuan Ma, Lei Hu

AI总结:

本文提出JWST发现的z>11星系候选体中的点状源可能是高红移超新星污染,并指出其仅占样本约10%,但若证实将深刻影响早期星系形成与恒星形成率密度的认识。

摘要:

近期利用詹姆斯·韦布空间望远镜对z>11星系的搜寻得到了出乎意料的大量候选天体,这意味着z>11星系的数密度至少比此前偏好的预测高出一个数量级。由此产生了一个问题:这些候选体中是否存在某些新型污染源。Yan等人(2023a)的候选样本共有87个 dropout 天体,是最大的一个样本,而我们注意到其中若干候选体呈点状。我们假设这些点源 dropout 可能是高红移超新星。进一步研究显示,它们中大多数的光谱能量分布确实可以用红移范围约z~1--15的超新星来解释,这支持了上述假设。然而,将这类点源 dropout 归因于超新星污染并不能消除这一紧张局面,因为它们仅占Yan等人样本的约10%。另一方面,在z>3处发现“污染性”超新星将带来一系列重要影响。颇具讽刺意味的是,z>10处超新星的存在仍将意味着,此前偏好的早期星系形成图景严重低估了这些红移处的全局恒星形成率密度。多历元JWST成像将是进一步检验这一假设的最简单且最高效的方式。

英文摘要:

The recent searches for z>11 galaxies using the James Webb Space Telescope have resulted in an unexpectedly high number of candidate objects, which imply at least an order of magnitude higher number density of z>11 galaxies than the previously favored predictions. A question has risen whether there are some new types of contaminants among these candidates. The candidate sample of Yan et al. (2023a), totalling 87 dropouts, is the largest one, and we notice that a number of these candidates are point-like. We hypothesize that the point-source dropouts could be supernovae at high redshifts. Further investigation shows that most of their spectral energy distributions indeed can be explained by supernovae at various redshifts from z ~ 1--15, which lends support to this hypothesis. Attributing such point-source dropouts to supernova contamination cannot eliminate the tension, however, because they only account for ~10% of the Yan et al.'s sample. On the other hand, the discovery of "contaminant" supernovae at z>3 will have a series of important implications. Ironically, the existence of supernovae at $z>10$ would still imply that the previously favored picture of early galaxy formation severely underestimates the global star formation rate density such redshifts. Multiple-epoch JWST imaging will be the simplest and yet the most efficient way to further test this hypothesis.

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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