宇宙对：DESI 对双活动星系核与偏移活动星系核的普查，作为大质量黑洞双星的前身
Cosmic Pairs: A DESI Census of Dual and Offset AGN as Precursors to Massive Black Hole Binaries
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中文总结 AI 辅助
该研究基于 DESI DR1 光谱数据，构建了超大样本双与偏移 AGN，结合 ASTRID 模拟揭示其演化特征，为 LISA 可探测的大质量黑洞并合提供了前身星系群样本。
中文摘要 AI 辅助
我们利用暗能量光谱仪（DESI）第一数据发布（DR1）的光谱数据，开展了双活动星系核（AGN）与偏移活动星系核的系统普查。在校正观测系统误差后，最终样本包含红移范围为 0 ≲ z ≲ 3.6 的 >7000 个双 AGN 和 27000 个含一个 AGN 的星系对。该样本在 0.2 ≲ z ≲ 0.4 区间将已知双 AGN 样本规模扩大了约 1-2 个数量级，纳入了约 50 个矮星系双 AGN 候选体（此前该区间仅已知寥寥数个），并使 z>2 处的普查样本量增至原来的 3 倍。双 AGN 倾向于分布在小间距处，这与并合触发 AGN 活动的机制一致。星系对的两个成员在恒星形成响应上存在差异：质量更大的主星系随间距变化很小，而质量较小的次星系在相同投影间距下，主序偏移量比匹配的非活动星系和单 AGN 伴星高约 0.3 dex。利用 ASTRID 模拟，我们预测 DESI 双 AGN 中心黑洞在 z ~ 0 前并合的比例随红移增加，在 z ~ 2 时达到约 76%；产生 LISA 可探测并合的比例在 z ~ 0.9 附近达到峰值约 37%。这些结果提供了同一项巡天中最大的、均匀选取的千秒差距尺度双 AGN 与偏移 AGN 候选体光谱样本，将其寄主星系与 AGN 人口统计学与 LISA 可探测的大质量黑洞并合前身星系群关联起来。
英文摘要
We present a systematic census of dual and offset active galactic nuclei (AGN) using spectroscopic data from the first data release (DR1) of the Dark Energy Spectroscopic Instrument (DESI). After correcting for observational systematics, our final sample contains $>7,000$ dual AGN and 27,000 galaxy pairs containing one AGN over the redshift range $0 \lesssim z \lesssim 3.6$. This sample expands the known dual AGN sample by $\sim 1-2$ orders of magnitude at $0.2 \lesssim z \lesssim 0.4$, includes $\sim 50$ dwarf dual AGN candidates in a regime where only a handful were previously known, and triples the census at $z>2$. Dual AGN are preferentially found at small separations, consistent with merger-driven triggering of AGN activity. The two members of a pair differ in their star formation response: the more massive (primary) host changes little with separation, while the less massive (secondary) lies $\sim 0.3$ dex above matched inactive and one-AGN companions at the same projected separation in main-sequence offset. Using ASTRID simulations, we predict that the fraction of DESI dual AGN whose central black holes will merge by $z \sim 0$ increases with redshift, reaching $\sim 76\%$ by $z \sim 2$, while the fraction producing LISA-detectable mergers peaks at $\sim 37\%$ near $z \sim 0.9$. These results provide the largest uniformly selected spectroscopic sample of kpc-scale dual and offset AGN candidates from a single survey, connecting their host-galaxy and AGN demographics to the progenitor population of massive black hole mergers detectable by LISA.
