标题： 推断扰动强引力透镜图像的暗物质子晕的浓度 显示英文标题

标题： Inferring the concentration of dark matter subhalos perturbing strongly lensed images

摘要： 我们证明，由低质量暗物质子晕引起的强透镜图像的扰动显著受到扰动子晕浓度的影响。 在$\Lambda$CDM 中预期的子晕浓度下，对于质量大于约$10^{10}M_\odot$的子晕，在哈勃望远镜（HST）分辨率下可以获得显著的浓度限制。 如果低质量子晕的浓度高于 CDM 中的预期波动，则也可以获得限制。 我们还发现，通过分辨率为$\sim 0.01''$的观测手段，可以很好地约束质量低至$\sim 10^8M_\odot$的扰动体的浓度，这种分辨率可以通过长基线干涉测量实现。 子晕的浓度在扰动的可探测性中也起着关键作用，因此只有质量为$\lesssim 10^9M_\odot$的高浓度扰动体才可能在 HST 分辨率下被探测到。 如果在透镜建模过程中未考虑$\Lambda$冷暗物质质量-浓度关系中的分散性，对于质量为$10^9 M_\odot$($10^{10} M_\odot$) 的次结构，推断出的次结构质量可能被偏差高达3(6)倍；如果在透镜拟合过程中同时变化质量和浓度，这种偏差可以被消除。 另外，可以稳健地推断出次结构扰动半径内的投影质量，该半径由其到被扰动透镜临界曲线的距离定义。 在有足够的检测数量的情况下，这些策略将使人们能够在约束低质量处的晕质量-浓度关系的同时，也约束质量函数，从而提供对暗物质物理以及小尺度原初功率谱的探测。 显示英文摘要

摘要： We demonstrate that the perturbations of strongly lensed images by low-mass dark matter subhalos are significantly impacted by the concentration of the perturbing subhalo. For subhalo concentrations expected in $\Lambda$CDM, significant constraints on the concentration can be obtained at HST resolution for subhalos with masses larger than about $10^{10}M_\odot$. Constraints are also possible for lower mass subhalos, if their concentrations are higher than the expected scatter in CDM. We also find that the concentration of lower mass perturbers down to $\sim 10^8M_\odot$ can be well-constrained with a resolution of $\sim 0.01''$, which is achievable with long-baseline interferometry. Subhalo concentration also plays a critical role in the detectability of a perturbation, such that only high concentration perturbers with mass $\lesssim 10^9M_\odot$ are likely to be detected at HST resolution. If scatter in the $\Lambda$CDM mass-concentration relation is not accounted for during lens modeling, the inferred subhalo mass can be biased by up to a factor of 3(6) for subhalos of mass $10^9 M_\odot$($10^{10} M_\odot$); this bias can be eliminated if one varies both mass and concentration during lens fitting. Alternatively, one may robustly infer the projected mass within the subhalo's perturbation radius, defined by its distance to the critical curve of the lens being perturbed. With a sufficient number of detections, these strategies will make it possible to constrain the halo mass-concentration relation at low masses in addition to the mass function, offering a probe of dark matter physics as well as the small-scale primordial power spectrum.