细丝在大规模一致性信号中的作用
The role of filaments in the large-scale conformity signal
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中文总结 AI 辅助
研究聚焦低质量中心星系的大规模一致性信号，通过模拟和算法测量不同环境下的信号，发现细丝区域及邻近大质量系统的潮汐力对其起关键作用，不同细丝特征下信号有差异，靠近相互作用大质量系统的低质量中心星系信号被放大。
中文摘要 AI 辅助
我们研究大规模一致性信号及其与大规模结构的联系，聚焦于低质量中心星系，排除过去是卫星的星系。通过DisPerSE算法识别不同环境（包括群组边缘、星系团边缘、细丝、细丝边缘及其他环境）来测量信号，以评估各部分对大规模一致性信号的贡献。使用IllustrisTNG300模拟和半解析模型MDPL2 - SAG的星系目录。结果表明细丝区域及邻近大质量系统的潮汐力在塑造大规模一致性信号中起关键作用。在SAG中，嵌入细丝区域的星系是主要贡献者，能重现信号整体形状和幅度；在TNG300中，排除过去是卫星的星系后，位于细丝区域的星系也呈现出连贯但较弱的一致性信号。研究还发现改变细丝厚度或考虑重叠区域的星系时信号无显著差异，且信号在高线性密度、短且高质量的细丝中增强，在低线性密度、长且低质量的细丝中也存在但幅度略低。最后，靠近相互作用大质量系统的低质量中心星系显示出放大的一致性信号，范围可达4 Mpc/h。
英文摘要
We investigate the large-scale conformity signal and its connection with the large-scale structure, focusing on low-mass central galaxies, after excluding galaxies that were satellites in the past. We measure the signal across different environments identified with the DisPerSE algorithm, including group outskirts, cluster outskirts, filaments, filament outskirts, and other environments (voids and walls) in order to assess how each population contributes to the large-scale conformity signal. We use the galaxy catalogs from the IllustrisTNG300 simulation and the semi-analytic model MDPL2-SAG. In SAG, galaxies embedded in filamentary regions emerge as the primary contributors to the large-scale conformity signal, closely reproducing its overall shape and amplitude. In TNG300, galaxies located in filamentary regions also exhibit a coherent, albeit weaker, conformity signal once galaxies that were satellites in the past are excluded. We also examine whether the signal depends on the adopted filament definition. We find no substantial differences when varying the filament thickness or considering galaxies in overlapping regions. Instead, the signal remains strong and largely insensitive to these differences. We then investigate the dependence of the conformity signal on filament linear density, length, and mass. The signal is enhanced in high-linear density, short, and high-mass filaments, but remains present in low-linear density, long, and low-mass filaments, although with a slightly lower amplitude. Finally, we find that low-mass central galaxies located in close proximity to interacting massive systems show an amplified conformity signal extending up to 4 Mpc/h. Overall, our results indicate that filamentary regions, and the tidal forces from neighboring massive systems play a fundamental role in shaping the large-scale conformity signal.
