We present a numerical evidence supporting the primordial origin of secondary halo bias even on the galactic mass scale. Analyzing the data from the TNG 300-1 simulations, we investigate the dependence of halo bias on the degree of misalignment between the protohalo inertia and initial tidal tensors, τ, measured at redshift, z _i =127. From the TNG 300-1 galactic halos in logarithmic mass range of 10.5 < m ≡ log[M/(h ^-1 M _⊙)] ≤ 13 identified at z=0, 0.5 and 1, a clear signal of τ bias is detected. For the case that τ is measured from the initial tidal field smoothed on the scale of R_f /(h ^-1Mpc) ≲ 1, the halo τ bias is found to be very similar in its tendency and amplitude to the spin bias at all of the three redshifts, if the effects of backsplash halos are properly eliminated. For the case of R_f /(h ^-1Mpc) = 2, the τ bias at z=1 turns out to behave like the age bias, diminishing rapidly in the range of m > 12. At z=0 and 0.5, however, the τ and age bias factors show large differences in their overall strengths, which is attributed to the dominant nonlinear effects that undermine the former but enhance the latter. Given these numerical results along with the previous finding [1] that τ shares a large amount of mutual information with the formation epochs and spin parameters of galactic halos, it is concluded that the origins of halo age and spin bias must be closely linked with the primordial factor, τ, and that the difference in the tendency between the two bias factors on the galactic mass scale reflects the multi-scale influence of τ on the halo secondary properties.

中文翻译：

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晕偏偏置对原晕形状与初始潮汐场对齐的依赖性


我们提供了一个数值证据，即使在银河系质量尺度上也支持次级晕偏置的原始起源。分析来自 TNG 300-1 模拟的数据，我们研究了光晕偏差对原光晕惯量和初始潮汐张量之间错位程度的依赖性，τ，在红移 z=127 处测量。从对数质量范围为 10.5 < m ≡ log[M/（^h-1M_⊙）] ≤ 13 的 TNG 300-1 星系晕中，在 z=0、0.5 和 1 处识别出 τ 偏置的明确信号。对于从初始潮汐场测量 τ 的情况，在 R_f /（^h-1Mpc） ≲ 1 的尺度上平滑，如果适当消除后挡光晕的影响，则发现光晕 τ 偏差在趋势和振幅上与所有三个红移的自旋偏差非常相似。对于 R_f /（^h-1Mpc） = 2 的情况，z=1 时的 τ 偏差表现为与年龄偏差类似，在 m > 12 范围内迅速减小。然而，在 z=0 和 0.5 时，τ 和年龄偏差因子在整体强度上表现出很大差异，这归因于破坏前者但增强后者的主要非线性效应。鉴于这些数值结果以及之前的发现 [1]，τ 与星系晕的形成纪元和自旋参数共享大量互信息，可以得出结论，光晕年龄和自旋偏差的起源必须与原始因子 τ 密切相关，并且两个偏差因子在星系质量尺度上的趋势差异反映了 τ 对halo 次要属性。