发表机构
Universitat de les Illes Balears; Stony Brook University（巴利阿里群岛大学; 石溪大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究小红点内部气体密度对极端质量比旋进引力波波形的影响，发现稠密内部模型可产生可测量偏差，LISA任务有望探测部分小红点事件，并区分不同内部模型。
AI 中文摘要
小红点（LRDs）是致密的宽线源，似乎包含嵌入在稠密气体中的吸积黑洞（BHs）。针对其中心环境提出的模型（包括准恒星、辐射黑洞包层和超爱丁顿吸积盘）预测了极端质量比旋进所探测半径处的气体密度，这些密度相差多个数量级。我们计算了质量在10至30倍太阳质量范围内的黑洞在一系列LRD内部模型中的旋进，包括气体带来的环境效应，并使用失配准则检验所产生的引力波波形能否与真空情形及彼此区分。稠密内部（类似Bondi的自由落体空腔和辐射包层）在几乎每一个可探测事件中都会产生与真空情形的可测量偏差。对流准恒星内部在黑洞质量小于约10^5倍太阳质量且红移小于约0.6时是可测量的，而共转盘则不会留下可测量的印记。在有利情况下，这些模型之间也可以相互区分。在红移大于3.9的14个JWST LRDs中，没有一个会因10倍太阳质量的伴星而被探测到，但在红移小于0.9的31个LRDs中，如果它们的黑洞质量比其维里估计值小约100倍，则有30个可被探测到，并且其中许多内部的印记是可测量的。在整个红移至6的LRD群体中，为期4年的LISA任务将产生0.08至0.8个可探测事件（对于10^5倍太阳质量的主黑洞和10倍太阳质量的伴星），若伴星质量为30倍太阳质量，则为1.5至15个，前提是LRD核以普通星系核的速率发生旋进。在稠密星团中，捕获为直接坠落，这一数字降至小于10^-4。
英文摘要
The Little Red Dots (LRDs) are compact, broad-line sources that appear to contain accreting black holes (BHs) embedded in dense gas. Proposed models for their central environments (including quasi-stars, radiative BH envelopes and super-Eddington accretion discs) predict gas densities at the radii probed by an extreme-mass-ratio inspiral that differ by many orders of magnitude. We compute the inspiral of a $10$--$30\Msun$ BH for a range of LRD interior models, including environmental effects from the gas, and test with a mismatch criterion whether the resulting waveforms can be distinguished from vacuum and from one another. Dense interiors (Bondi-like free-fall cavities and radiative envelopes) produce measurable deviations from vacuum in essentially every detectable event. Convective quasi-star interiors are measurable for $\MBH\lesssim10^5\Msun$ and $z\lesssim0.6$, while a co-rotating disc leaves no measurable imprint. In favorable cases the models are also mutually distinguishable. None of the 14 JWST LRDs at $z>3.9$ would be detectable with a $10\Msun$ companion, but 30 of 31 LRDs at $z<0.9$ would be if their black holes are $\sim100$ times less massive than their virial estimates, and in many of them the interior's imprint would be measurable. Across the LRD population to $z=6$, a 4-yr LISA mission would yield $0.08$--$0.8$ detectable events for $10^5\Msun$ hosts and $10\Msun$ companions ($1.5$--$15$ for $30\Msun$) if LRD nuclei host inspirals at the rate of ordinary galactic nuclei. In dense clusters, where captures are plunges, this falls to $\lesssim10^{-4}$.
Comments8 pages, 4 figures
