针对亚太阳质量引力波候选体S251112cm的为期两个月的星系定向近红外后续观测：探测电磁对应体场景
A Two-month, Galaxy-targeted NIR Follow-up of the Sub-solar-mass Gravitational Wave Candidate S251112cm: Probing Electromagnetic Counterpart Scenarios
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中文总结 AI 辅助
针对亚太阳质量引力波候选体S251112cm，开展两个月星系定向近红外后续观测，未发现可信暂现源，排除高抛射质量的明亮千新星构型，验证了宿主加权框架的适用性。
中文摘要 AI 辅助
S251112cm是一个距离为93±27 Mpc的致密双星并合候选体，其推断概率很高，至少有一个成分低于1 M⊙。该事件为理论预测但尚未证实的亚太阳质量并合候选体的电磁后续观测提供了罕见的测试案例。受预测近红外（NIR）在数周至数月内会发出明亮辐射的场景启发，我们开展了一项为期约两个月的深场、星系定向的UKIRT J波段观测活动，通过结合三维定位概率和WISE W1光度（作为恒星质量代理）的排名来优先选择宿主候选体。在约9000个候选宿主中，我们监测了59个，对应累积加权宿主先验的7.7%。差值成像显示，在J~22-23 mag（AB）的典型深度下，没有发现可信的暂现源。在该距离下，Ic-BL型超新星模板和AT 2017gfo样千新星（KN）模板——包括时间偏移至Δt~60天的变体——在监测宿主的多个epoch中都会保持在我们的中值深度以上。通过条件加权一致分数图与标准KN模型网格的比较表明，具有高动力学质量和风抛射质量的明亮构型被强烈排除，而光度较低的构型在很大程度上仍然是允许的。尽管这些限制受宿主限制，并不构成对整个事件的排除，但该观测活动为亚太阳质量并合引力波类提供了首个长基线、深近红外后续观测的实证案例研究，并展示了适用于未来星系定向观测活动的宿主加权框架。
英文摘要
S251112cm is a nearby ($93 \pm 27$~Mpc) compact-binary merger candidate with a high inferred probability that at least one component is below $1\,M_\odot$. This event provides a rare test case for electromagnetic follow-up of a theoretically predicted but unconfirmed sub-solar-mass merger candidate. Motivated by scenarios predicting NIR-bright emission over weeks to months, we carried out a deep, galaxy-targeted UKIRT $J$-band campaign over approximately two months, prioritizing host candidates by a ranking that combines the three-dimensional localization probability with WISE W1 luminosity as a stellar-mass proxy. Of $\sim9000$ candidate hosts, we monitored 59, corresponding to 7.7\% of the cumulative weighted host prior. Difference imaging reveals no convincing transient down to typical depths of $J\sim22$--23~mag (AB). At this distance, both a Type~Ic-BL supernova template and an AT\,2017gfo-like KN template---including time-shifted variants up to $Δt \sim 60$~days---would have remained above our median depth for multiple epochs within the monitored hosts. Comparison with a canonical KN model grid, summarized through conditional weighted consistent-fraction maps, shows that bright configurations with high dynamical and wind-ejecta masses are strongly disfavored, while less luminous configurations remain largely permissible. While these constraints are host-limited and do not constitute an event-wide exclusion, this campaign provides the first empirical case study of long-baseline, deep NIR follow-up for a sub-solar-mass merger GW class and demonstrates a host-weighted framework applicable to future galaxy-targeted campaigns.
