arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2407.02044astro-ph.CO
收藏

引力与暗能量的界面

The interface of gravity and dark energy

Kristen Lackeos, Richard Lieu

AI总结:

本文研究暗能量在大尺度上对星系束缚轨道和星系团维里化气体的影响,提出广义维里半径与暗物质晕截断,并用于 Abell 1835 的 X 射线及弱透镜观测。

摘要:

在足够大的半径处,暗能量会改变以下两种行为:(a)星系周围的束缚轨道,以及(b)星系团中维里化气体的行为。暗能量还为星系团的暗物质晕提供了一个自然的截断。在(a)中,存在一个最大圆轨道,超过该轨道后周期运动便不再可能,而临界束缚附近的轨道演化可利用绝热不变量积分进行解析计算。这一发现与宽星系对研究有关。在(b)中,暗能量使得有必要使用广义维里定理来描述星系团外围的气体。当与借助暗能量的重子逃逸条件相结合时,所得结果给出一个半径,超过该半径后持续建立热化重子的流体静力晕便无法维持。这引出一个具有理论依据的维里半径。我们利用该理论探究星系团重子晕的结构,并将其应用于星系团 Abell 1835 的 X 射线和弱引力透镜数据。我们发现,其外围气体从约 1.3 Mpc(即“内”维里半径)开始显著偏离流体静力平衡。我们还为 A1835 定义了一个依赖于模型的暗物质晕截断半径。该暗物质截断给出星系团总质量约 7×10^15 M⊙ 的上限。此外,在给定暗物质截断半径的情况下,可以推导出一个“外”流体静力平衡截断半径。星系团气体输运和湍流区域出现在内、外截断半径之间。

英文摘要:

At sufficiently large radii dark energy modifies the behavior of (a) bound orbits around a galaxy and (b) virialized gas in a cluster of galaxies. Dark energy also provides a natural cutoff to a cluster's dark matter halo. In (a) there exists a maximum circular orbit beyond which periodic motion is no longer possible, and orbital evolution near critical binding is analytically calculable using an adiabatic invariant integral. The finding implicates the study of wide galaxy pairs. In (b), dark energy necessitates the use of a generalized Virial Theorem to describe gas at the outskirts of a cluster. When coupled to the baryonic escape condition, aided by dark energy, the results is a radius beyond which the continued establishment of a hydrostatic halo of thermalized baryons is untenable. This leads to a theoretically motivated virial radius. We use this theory to probe the structure of a cluster's baryonic halo and apply it to X-ray and weak-lensing data collected on cluster Abell 1835. We find that gas in its outskirts deviates significantly from hydrostatic equilibrium beginning at $\sim 1.3\ {\rm Mpc}$, the `inner' virial radius. We also define a model dependent dark matter halo cutoff radius to A1835. The dark matter cutoff gives an upper limit to the cluster's total mass of $\sim7\times 10^{15}M_{\odot}$. Moreover, it is possible to derive an `outer' hydrostatic equilibrium cutoff radius given a dark matter cutoff radius. A region of cluster gas transport and turbulence occurs between the inner and outer cutoff radii.

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。

↑