Tidal disruption of star clusters in galaxy formation simulations
Tidal disruption of star clusters in galaxy formation simulations
复制标题
星系形成模拟中星团的潮汐破坏
DOI：
10.1093/mnras/stac1751
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发表时间：
2022
影响因子：
4.8
通讯作者：
Gnedin, Oleg Y.
中科院分区：
文献类型：
--
作者：
Meng, Xi;Gnedin, Oleg Y.
我们利用银河系大小的星系的宇宙学模拟来研究大质量星团所经历的潮汐场的演化。我们模拟中的星团在形成后的最初几百密尔内经历了最强的潮汐力，此时潮汐张量的最大特征值达到 104Gyr−2 的数倍。大约 1 Gyr 后，潮汐场稳定在较低值，中值 λm∼ 3 × 103Gyr−2。星团花在高潮汐强度 (λm> 3 × 104Gyr−2) 区域的时间比例也随着其年龄的增长而减少，从形成后立即的约 20% 减少到 1 Gyr 后的不到 1%。在早期，原位星团经历了相似的潮汐场，而在较老的年龄，原位星团由于它们在宿主星系中的轨道较低，通常会经历更强的潮汐场。这种差异反映在星团的生存上：我们研究了在模拟运行时计算的星团破坏，发现相同初始质量的异位星团通常在最后一个可用的模拟快照中比原位星团具有更高的束缚分数。
We investigate the evolution of the tidal field experienced by massive star clusters using cosmological simulations of Milky Way-sized galaxies. Clusters in our simulations experience the strongest tidal force in the first few hundred Myr after formation, when the maximum eigenvalue of the tidal tensor reaches several times 104Gyr−2. After about 1 Gyr the tidal field plateaus at a lower value, with the median λm∼ 3 × 103Gyr−2. The fraction of time clusters spend in high tidal strength (λm> 3 × 104Gyr−2) regions also decreases with their age from ∼20 per cent immediately after formation to less than 1 per cent after 1 Gyr. At early ages both thein situandex situclusters experience similar tidal fields, while at older ages thein situclusters in general experience stronger tidal field due to their lower orbits in host galaxy. This difference is reflected in the survival of clusters: we looked into cluster disruption calculated in simulation runtime and found thatex situstar clusters of the same initial mass typically end up with higher bound fraction at the last available simulation snapshot than thein situones.