Uncertainties associated with the backward integration of dwarf satellites using simple parametric potentials
Uncertainties associated with the backward integration of dwarf satellites using simple parametric potentials
复制标题
使用简单参数势对矮卫星进行后向积分相关的不确定性
DOI：
10.1093/mnras/stac404
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发表时间：
2022
影响因子：
4.8
通讯作者：
Bell, Eric F.
中科院分区：
文献类型：
--
作者：
D’Souza, Richard;Bell, Eric F.
为了对银河系矮星系的轨道进行后向积分，近年来已经投入了大量的努力来约束它们的初始相空间坐标。然而，同样重要的是对矮星系随时间推移所经历的潜力的假设，特别是考虑到MW目前正在吸积大麦哲伦云（LMC）的事实。在这项工作中，使用暗物质的放大模拟，我们测试是否使用共同的参数形式的潜力是足够的成功向后整合的subhaloes从他们现在的位置的轨道。我们参数化恢复的轨道，并比较它们与那些从模拟。我们发现，简单的对称参数形式的潜在未能捕捉的复杂性和不均匀性的真实潜在的经历的subhaloes。更具体地说，模拟最近的大规模吸积像的LMC作为两个球形参数的潜力的总和导致恢复的轨道参数的重大错误。这些错误的对手所造成的，由于（a）30%的MW维里质量的不确定性和（B）没有模拟的潜力，最近吸积的大质量卫星。我们的工作表明，（i）一些MW矮星的恢复轨道的参数的不确定性可能被低估，（ii）研究人员应该表征固有的不确定性，他们选择的集成技术和假设的潜力对宇宙学放大模拟的MW，其中包括最近吸积的LMC。
In order to backward integrate the orbits of Milky Way (MW) dwarf galaxies, much effort has been invested in recent years to constrain their initial phase-space coordinates. Yet equally important are the assumptions on the potential that the dwarf galaxies experience over time, especially given the fact that the MW is currently accreting the Large Magellanic Cloud (LMC). In this work, using a dark-matter-only zoom-in simulation, we test whether the use of common parametric forms of the potential is adequate to successfully backward integrate the orbits of the subhaloes from their present-day positions. We parametrize the recovered orbits and compare them with those from the simulations. We find that simple symmetric parametric forms of the potential fail to capture the complexities and the inhomogeneities of the true potential experienced by the subhaloes. More specifically, modelling a recent massive accretion like that of the LMC as a sum of two spherical parametric potentials leads to substantial errors in the recovered parameters of the orbits. These errors rival those caused due to (a) a 30 per cent uncertainty in the virial mass of the MW and (b) not modelling the potential of the recently accreted massive satellite. Our work suggests that (i) the uncertainties in the parameters of the recovered orbits of some MW dwarfs may be underestimated and that (ii) researchers should characterize the uncertainties inherent to their choice of integration techniques and assumptions of the potential against cosmological zoom-in simulations of the MW, which include a recently accreted LMC.