Inferring the concentration of dark matter subhaloes perturbing strongly lensed images
Inferring the concentration of dark matter subhaloes perturbing strongly lensed images
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DOI：
10.1093/mnras/stab2209
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发表时间：
2020-11
影响因子：
4.8
通讯作者：
Q. Minor;M. Kaplinghat;Tony H. Chan;E. Simon
中科院分区：
文献类型：
--
作者：
Q. Minor;M. Kaplinghat;Tony H. Chan;E. Simon
我们证明，低质量暗物质亚。镜头的扰动受到扰动的浓度的显着影响。 \ rm m} _ \ odot $也是可能的。质量亚卤素，如果它们的浓度高于CDM中的预期散射。只有质量$ \ lysesim 10^9 \的高浓度遗物， {\ rm m} _ \ odot $在HST分辨率上可能会检测到。 \ rm m} _ \ odot $）;推断subhalo的扰动半径内的预计质量，其距离与透镜的临界曲线的距离定义，这些策略将有可能限制halo质量 - 浓度的关系，除了质量功能，还可以在低质量上进行小质量功能。
We demonstrate that the perturbations of strongly lensed images by low-mass dark matter subhaloes are significantly impacted by the concentration of the perturbing subhalo. For subhalo concentrations expected in Lambda cold dark matter (ΛCDM), significant constraints on the concentration can be obtained at Hubble Space Telescope (HST) resolution for subhaloes with masses larger than about $10^{10}\, {\rm M}_\odot$. Constraints are also possible for lower mass subhaloes, if their concentrations are higher than the expected scatter in CDM. We also find that the concentration of lower mass perturbers down to $\sim 10^8\, {\rm M}_\odot$ can be well constrained with a resolution of ∼0.01 arcsec, 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 $\lesssim 10^9\, {\rm M}_\odot$ are likely to be detected at HST resolution. If scatter in the ΛCDM mass–concentration relation is not accounted for during lens modelling, the inferred subhalo mass can be biased by up to a factor of 3 (6) for subhaloes of mass $10^9 \, {\rm M}_\odot \,(10^{10} \, {\rm M}_\odot$); 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.