标题： 观测到的星系特殊速度分布函数 显示英文标题

标题： The observed distribution function of peculiar velocities of galaxies

摘要： 我们给出了本星系群（距离本星系群50 Mpc范围内）一个代表性星系样本的观测速度弥散分布函数的首次测定结果，其中包括了广泛的聚类性质。 我们详细探讨了采样和距离测量中的不确定性对估计分布函数的影响。 观测到的速度弥散分布函数与早期引力聚类预测一致，涵盖了从场星系到丰富星团的整个速度弥散范围，尺度高达50 Mpc (H=100)。 在最简单的自洽模型中，宇宙中大部分的非均匀质量集中在星系或者它们的晕中。 我们估计，在距离我们50 Mpc (H=100)的范围内，大尺度流的“马赫数”约为0.8，这包括了星团中高弥散星系的影响。 显示英文摘要

摘要： We give the first determination of the observed peculiar velocity distribution function for a representative sample of galaxies (within 50 Mpc (H=100) of the Local Group), which includes a wide range of clustering properties. We explore in detail the effects of uncertainties in sampling and in distance measures on the estimated distribution function. The observed distribution function is consistent with an earlier prediction of gravitational clustering, over the entire range of peculiar velocities, from field galaxies to rich clusters, on scales up to 50 Mpc (H=100). In the simplest consistent model, most of the inhomogeneous mass of the Universe is in galaxies or their halos. We estimate the ``Mach Number'' for the bulk flow within 50 Mpc (H=100) from us to be approximately 0.8, which includes the effect of high-dispersion galaxies in clusters.