论文标题

通过扩展的快速动作最小化方法追踪观察到的星系的环境历史

Tracing the environmental history of observed galaxies via extended fast action minimization method

论文作者

Sarpa, Elena, Longobardi, Alessia, Kraljic, Katarina, Veropalumbo, Alfonso, Schimd, Carlo

论文摘要

我们提出了扩展快速动作最小化方法(EFAM)的新应用,该方法旨在评估环境在塑造星系进化中的作用。我们通过测试针对磁性流体动力学模拟的EFAM预测来验证我们的方法。我们将模拟的Z〜0快照视为我们观察到的目录,并使用星系的重建轨迹来对宇宙结构的演变进行建模。在统计水平上,重建目录中的空隙,床单,细丝和簇所占据的体积(VFF)的比例(VFF)在$1σ$之内同意,并根据模拟的高红色快速快照估算了VFF。 EFAM结构的局部准确性是通过计算正规网格细胞上模拟目录P的纯度来评估其纯度的。最多z = 1.2,簇的簇具有0.58 <p <0.93,细丝在0.90 <p <0.99中变化,床单显示为0.78 <p <0.92,最好用0.90 <p <0.92识别空隙。随着红移的增加,由于其不同的偏见和数量密度,比较重建的示踪剂和模拟星系变得更加困难,并且纯度降低到p〜0.6。我们通过通过宇宙网络追踪其轨迹,并将其观察到的气体分数($ f_ \ mathrm {gas} $)与在不同结构中花费的时间联系起来,从而检索了单个星系的环境历史。对于集群和丝状的星系,EFAM重现了$ f_ \ mathrm {gas} $的变化,这是由1.5 $σ$统计协议的仿真所追踪的振动/infall的函数(降低了2.5 $ c $ fillymass Galaxies in Fillaments中的统计协议)。这些结果支持EFAM在观察数据中的应用,以研究观察到的星系特性的环境依赖性,并基于轻单观测提供了一种补充方法。

We present a novel application of the extended Fast Action Minimization method (eFAM) aimed at assessing the role of the environment in shaping galaxy evolution. We validate our approach by testing eFAM predictions against the Magneticum hydrodynamical simulation. We consider the z~0 snapshot of the simulation as our observed catalogue and use the reconstructed trajectories of galaxies to model the evolution of cosmic structures. At the statistical level, the fraction of volume (VFF) occupied by voids, sheets, filaments, and clusters in the reconstructed catalogues agrees within $1σ$ with the VFF estimated from the high-redshift snapshots of the simulation. The local accuracy of eFAM structures is evaluated by computing their purity with respect to the simulated catalogues, P, at the cells of a regular grid. Up to z=1.2, clusters have 0.58<P<0.93, filaments vary in 0.90<P<0.99, sheets show 0.78<P<0.92, and voids are best identified with 0.90<P<0.92. As redshift increases, comparing reconstructed tracers and simulated galaxies becomes more difficult due to their different biases and number densities and the purity decreases to P~0.6. We retrieve the environmental history of individual galaxies by tracing their trajectories through the cosmic web and relate their observed gas fraction, $f_\mathrm{gas}$, with the time spent within different structures. For galaxies in clusters and filaments, eFAM reproduces the variation of $f_\mathrm{gas}$ as a function of the redshift of accretion/infall as traced by the simulations with a 1.5 $σ$ statistical agreement (which decreases to 2.5 $σ$ statistical agreement for low-mass galaxies in filaments). These results support the application of eFAM to observational data to study the environmental dependence of observed galaxy properties, offering a complementary approach to that based on light-cone observations.

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