The linear velocity field of 2MASS Redshift Survey, Ks= 11.75 galaxies: constraints on β and bulk flow from the luminosity function
The linear velocity field of 2MASS Redshift Survey, Ks= 11.75 galaxies: constraints on β and bulk flow from the luminosity function
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DOI：
10.1111/j.1365-2966.2012.21210.x
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发表时间：
2012-02
影响因子：
4.8
通讯作者：
E. Branchini;M. Davis;A. Nusser
中科院分区：
文献类型：
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作者：
E. Branchini;M. Davis;A. Nusser
使用几乎全天空Ks= 11.75的2 MASS红移巡天（2 MRS; Huchra等人）在145000个星系中，我们重建了基本的奇特速度场，并将宇宙学的体流限制在100 h−1 Mpc以内。这些结果是通过最大化概率来估计一个星系的绝对星等，给出其观测到的视星等和红移。在深度为1060 h−1 Mpc时，我们发现了与Λ冷暗物质模型的理论预测一致的整体流。使似然性最大化的重建的特有速度场由参数β= 0.32 ± 0.08表征。这两个结果都与先前使用较浅的Ks= 11.25 2 MRS巡天的12.3万个星系获得的结果一致。在我们的分析中，我们发现2 MRS星系的光度函数很难用Schechter形式来拟合，并且光度的演化使得物体随着红移的增加而变暗，满足L（z）=L（z= 0）（1 +z）+2.7 ± 0.15。
Using the nearly full-sky Ks= 11.75 2MASS Redshift Survey (2MRS; Huchra et al.) of ∼45 000 galaxies, we reconstruct the underlying peculiar velocity field and constrain the cosmological bulk flow within ∼100 h−1 Mpc. These results are obtained by maximizing the probability to estimate the absolute magnitude of a galaxy given its observed apparent magnitude and redshift. At a depth of ≈60 h−1 Mpc, we find a bulk flow in agreement with the theoretical predictions of the Λ cold dark matter model. The reconstructed peculiar velocity field that maximizes the likelihood is characterized by the parameter β= 0.32 ± 0.08. Both results are in agreement with those obtained previously using the ∼23 000 galaxies of the shallower Ks= 11.25 2MRS survey. In our analysis, we find that the luminosity function of 2MRS galaxies is poorly fitted by the Schechter form and that luminosity evolves such that objects become fainter with increasing redshift according to L(z) =L(z= 0)(1 +z)+2.7 ± 0.15.