重建极端区域的银河系轨道（ROGER）II：在我们理解星系群中投影相空间的可靠性
Reconstructing Orbits of Galaxies in Extreme Regions (ROGER) II: reliability of projected phase-space in our understanding of galaxy populations
摘要：
我们连接星系的性质与它们的轨道分类分析的样本的星系与恒星质量$M_{\star} \geq 10^{8.5}h^{-1}M_\odot$居住在和周围的质量$M_{200} > 10^{15}h^{-1}M_\odot$在红移$z=0$的大规模和孤立的星系团。星系人口是通过应用半解析模型的星系形成SAG的宇宙学模拟MultiDark Planck 2。我们分类星系考虑他们的真实轨道（3D）和他们的投影相空间位置使用ROGER代码（2D）。我们定义了五个类别：星系团、最近落入星系团的星系、后溅星系、下落星系和闯入者星系。对于每一类，我们分析的$g-r$颜色，特定的恒星形成率（sSFR），和恒星年龄，作为恒星质量的函数。对于3D类，我们发现，星系团星系有最低的sSFR，是最红的和最古老的，预期从环境的影响。后溅星系的性质介于星团和最近的落星系之间。对于每个2D类，我们发现其他类的重要污染。我们发现有必要将红色和蓝色的星系群分开，以便对2D数据进行更真实的分析。对于红色种群，2D结果与3D预测非常一致。然而，当考虑蓝色星族时，2D分析仅为最近的坠入星系，坠入星系和闯入星系提供可靠的结果。
英文摘要：
We connect galaxy properties with their orbital classification by analysing a sample of galaxies with stellar mass $M_{\star} \geq 10^{8.5}h^{-1}M_\odot$ residing in and around massive and isolated galaxy clusters with mass $M_{200} > 10^{15}h^{-1}M_\odot$ at redshift $z=0$. The galaxy population is generated by applying the semi-analytic model of galaxy formation SAG on the cosmological simulation MultiDark Planck 2. We classify galaxies considering their real orbits (3D) and their projected phase-space position using the ROGER code (2D). We define five categories: cluster galaxies, galaxies that have recently fallen into a cluster, backsplash galaxies, infalling galaxies, and interloper galaxies. For each class, we analyse the $g-r$ colour, the specific star formation rate (sSFR), and the stellar age, as a function of the stellar mass. For the 3D classes, we find that cluster galaxies have the lowest sSFR, and are the reddest and the oldest, as expected from environmental effects. Backsplash galaxies have properties intermediate between the cluster and recent infaller galaxies. For each 2D class, we find an important contamination by other classes. We find it necessary to separate the galaxy populations in red and blue to perform a more realistic analysis of the 2D data. For the red population, the 2D results are in good agreement with the 3D predictions. Nevertheless, when the blue population is considered, the 2D analysis only provides reliable results for recent infallers, infalling galaxies and interloper galaxies.
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