用数值模拟对低质量次晕生存和湮灭光度的照射
Shedding light on low-mass subhalo survival and annihilation luminosity with numerical simulations
摘要：
在这项工作中，我们进行了一套专门设计的数值模拟，以进一步阐明暗物质（DM）subhalo生存在质量尺度相关的伽马射线DM搜索，一个话题受到激烈的辩论。具体来说，我们已经开发并采用了改进版本的DASH，GPU $N$体代码，以前所未有的准确性研究低质量subhaloes内的银河系般的光环的演变，达到太阳质量和亚秒差距的分辨率在我们的模拟。我们模拟不同的质量，浓度和轨道特性的subhaloes，并考虑银河系本身的引力势的影响。更具体地说，我们分析了subhaloes的束缚质量分数和湮灭光度的演变，发现大多数subhaloes生存到现在的时间，即使在某些情况下，他们失去了超过99%的质量吸积。宿主中的重子会引起更严重的质量损失，特别是当次晕轨道与银盘更平行时。许多这样的次晕穿过太阳的银河系中心半径，因此更容易从地球上探测到它们的湮灭通量。我们发现，在太阳附近的一个近心点的DM只有晕轨道的subhaloes失去70-90%的初始湮灭光度在红移为零，增加到99%时，重子也包括在主机。我们发现，在近心点的有效潮汐场的子晕的质量损失之间有很强的关系。事实上，许多对浓度、轨道参数、宿主势和重子分量的依赖都可以通过这个单一参数来解释。除了阐明低质量银河系subhaloes的生存，我们的研究结果可以提供详细的预测，这将有助于当前和未来的探索DM的性质。
英文摘要：
In this work, we carry out a suite of specially-designed numerical simulations to shed further light on dark matter (DM) subhalo survival at mass scales relevant for gamma-ray DM searches, a topic subject to intense debate nowadays. Specifically, we have developed and employed an improved version of DASH, a GPU $N$-body code, to study the evolution of low-mass subhaloes inside a Milky Way-like halo with unprecedented accuracy, reaching solar-mass and sub-parsec resolution in our simulations. We simulate subhaloes with varying mass, concentration, and orbital properties, and consider the effect of the gravitational potential of the Milky Way galaxy itself. More specifically, we analyze the evolution of both the bound mass fraction and annihilation luminosity of subhaloes, finding that most subhaloes survive until present time, even though in some cases they lose more than 99% of their mass at accretion. Baryons in the host induce a much more severe mass loss, especially when the subhalo orbit is more parallel to the galactic disk. Many of these subhaloes cross the solar galactocentric radius, thus making it easier to detect their annihilation fluxes from Earth. We find subhaloes orbiting a DM-only halo with a pericentre in the solar vicinity to lose 70-90% of their initial annihilation luminosity at redshift zero, which increases up to 99% when baryons are also included in the host. We find a strong relation between subhalo's mass loss and the effective tidal field at pericentre. Indeed, much of the dependence on concentration, orbital parameters, host potential and baryonic components can be explained through this single parameter. In addition to shedding light on the survival of low-mass galactic subhaloes, our results can provide detailed predictions that will aid current and future quests for the nature of DM.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
