论文标题
斯隆数字天空调查奇特的速度目录
The Sloan Digital Sky Survey Peculiar Velocity Catalogue
论文作者
论文摘要
我们使用Sloan Digital Sky Survey(SDSS)的数据提出了一个新的距离和奇特速度(PV)目录(PVS)。这个$ 7016 \,\ mathrm {deg}^{2} $均质样本包括迄今为止生产的最大的特殊速度集,并将PV调查的范围扩展到$ Z = 0.1 $。我们的基于SDSS的FP距离测量值的平均不确定性为23%。除了数据外,我们生成了2,048个模拟星系目录的集合,可重现数据选择功能,并用于验证我们的拟合管道并检查系统错误。我们发现样品内的群体丰富度和平均表面亮度之间的显着趋势,这可能暗示了FP内的环境依赖性或未解决的系统学的存在,并且可能导致偏见的特殊速度。使用多个FP拟合作为组丰富度的函数来删除这,这是通过新的分析推导在非平凡限制上进行的整体分析的过程。我们的目录已校准为Cosmicflows-III样品的零点,不确定性为$ 0.004 $ dex(不包括Cosmic Frianciance或Cosmicflows-III本身中的错误),使用独立的交叉检查与我们的本地velocity的2M++重新构造。最后,作为我们新目录的可能性的一个示例,我们获得了初步的散装流量测量值,深度为$ 135 \,h^{ - 1} \ mathrm {mpc} $。我们发现在高红移处的大量流量略大,尽管这可能是由于SDSS SDSS PV足迹之外的Shapley超级收集器的存在引起的。
We present a new catalogue of distances and peculiar velocities (PVs) of $34,059$ early-type galaxies derived from Fundamental Plane (FP) measurements using data from the Sloan Digital Sky Survey (SDSS). This $7016\,\mathrm{deg}^{2}$ homogeneous sample comprises the largest set of peculiar velocities produced to date and extends the reach of PV surveys up to a redshift limit of $z=0.1$. Our SDSS-based FP distance measurements have a mean uncertainty of 23%. Alongside the data, we produce an ensemble of 2,048 mock galaxy catalogues that reproduce the data selection function, and are used to validate our fitting pipelines and check for systematic errors. We uncover a significant trend between group richness and mean surface brightness within the sample, which may hint at an environmental dependence within the FP or the presence of unresolved systematics, and can result in biased peculiar velocities. This is removed using multiple FP fits as function of group richness, a procedure made tractable through a new analytic derivation for the integral of a 3D Gaussian over non-trivial limits. Our catalogue is calibrated to the zero-point of the CosmicFlows-III sample with an uncertainty of $0.004$ dex (not including cosmic variance or the error within CosmicFlows-III itself), which is validated using independent cross-checks with the predicted zero-point from the 2M++ reconstruction of our local velocity field. Finally, as an example of what is possible with our new catalogue, we obtain preliminary bulk flow measurements up to a depth of $135\,h^{-1}\mathrm{Mpc}$. We find a slightly larger-than-expected bulk flow at high redshift, although this could be caused by the presence of the Shapley supercluster which lies outside the SDSS PV footprint.