相关论文: Are Recent Peculiar Velocity Surveys Consistent?

We have compared the bulk flow of recent large-scale peculiar velocity surveys (SMAC, SC, Lauer and Postman, Willick, EFAR and Tonry's SNIa sample) to each other, allowing for the errors due to sparse sampling. We conclude that, contrary to…

Peculiar velocity surveys have non-uniform spatial distributions of tracers, so that the bulk flow estimated from them does not correspond to that of a simple volume such as a sphere. Thus bulk flow estimates are generally not strictly…

We report first results from the ``Streaming Motions of Abell Clusters'' (SMAC) project, an all-sky Fundamental Plane survey of 699 early-type galaxies in 56 clusters between ~3000 km/s and ~14000 km/s. For this sample, with a median…

The large-scale bulk flow implied by the measurements of distances to brightest cluster members within 15,000 km/s by Lauer and Postman has the potential to put strong constraints on, or to even rule out, various models of large-scale…

It has been argued recently that the galaxy peculiar velocity field provides evidence of excessive power on scales of $50\hmpc$, which seems to be inconsistent with the standard $\Lambda$CDM cosmological model. We discuss several…

We present an analysis comparing the bulk--flow measurements for six recent peculiar velocity surveys, namely, ENEAR, SFI, RFGC, SBF and the Mark III singles and group catalogs. We study whether the direction of the bulk--flow estimates are…

We analyze in detail the peculiar velocity field traced by 56 clusters within 120 h^-1 Mpc in the Streaming Motions of Abell Clusters (SMAC) sample. The bulk flow of the SMAC sample is 687 +- 203 km/s, toward l = 260 +- 13, b = 0 +- 11. We…

Observations have repeatedly confirmed the presence of large-scale peculiar motions in the universe, commonly referred to as ``bulk flows''. These are vast regions of the observable universe, typically spanning scales of several hundred…

In this paper we investigate how observational effects could possibly bias cosmological inferences from peculiar velocity measurements. Specifically, we look at how bulk flow measurements are compared with theoretical predictions. Usually…

For over a decade there have been contradictory claims in the literature about whether the local bulk flow motion of galaxies is consistent or in tension with the $\Lambda$CDM model. While it has become evident that systematics affect bulk…

Peculiar velocities of clusters of galaxies can be measured by studying the fluctuations in the cosmic microwave background (CMB) generated by the scattering of the microwave photons by the hot X-ray emitting gas inside clusters. While for…

We measure the bulk flow of the local Universe using the 6dF Galaxy Survey peculiar velocity sample (6dFGSv), the largest and most homogeneous peculiar velocity sample to date. 6dFGSv is a Fundamental Plane sample of $\sim10^4$ peculiar…

We calculate the theoretical expectation for the bulk motion of a large scale survey of the type recently carried out by Lauer and Postman. Included are the effects of survey geometry, errors in the distance measurements, clustering…

We address recently reported anomalously large bulk flows on scales of 100 Mpc/h and beyond. These coherent motions of galaxies challenge the standard LCDM concordance model as well as a large class of competitive models of dark energy and…

The SMAC project is a Fundamental Plane peculiar velocity survey of 56 clusters of galaxies to a depth of cz ~ 12000 km/s. We present here some results from the analysis of the SMAC velocity field, focussing on three specific features: the…

I review the recent developments in the analysis of cosmic flow data, in particular, latest results of bulk flow measurements, comparison between redshift and peculiar velocity catalogs with emphasis on the measured value of the $\beta…

The Cosmicflows-2 catalogue is a compendium of peculiar velocity measurements. While it has many objects in common with the COMPOSITE catalogue, a previously analysed collection of peculiar velocity data found to give an unexpectedly large…

Maximum Likelihood estimation of the bulk flow from radial peculiar motions of galaxies, generally assumes a constant velocity field inside the survey volume. The assumption is inconsistent with the definition of the bulk flow as the…

The low order moments, such as the bulk flow and shear, of the large scale peculiar velocity field are sensitive probes of the matter density fluctuations on very large scales. In practice, however, peculiar velocity surveys are usually…

I address the following issues: All bulk velocity measurements (but one) are consistent with our standard gravitational instability theory. New accurate data and reconstruction methods allow high-resolution dynamical analysis nearby,…