# Testing the minimum variance method for estimating large‐scale velocity moments

@article{Agarwal2012TestingTM, title={Testing the minimum variance method for estimating large‐scale velocity moments}, author={Shankar Agarwal and Hume A. Feldman and Richard Watkins}, journal={Monthly Notices of the Royal Astronomical Society}, year={2012}, volume={424}, pages={2667-2675} }

The estimation and analysis of large-scale bulk flow moments of peculiar velocity surveys is complicated by non-spherical survey geometry, the non-uniform sampling of the matter velocity field by the survey objects and the typically large measurement errors of the measured line-of-sight velocities. Previously, we have developed an optimal ‘minimum variance’ (MV) weighting scheme for using peculiar velocity data to estimate bulk flow moments for idealized, dense and isotropic surveys with… Expand

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#### References

SHOWING 1-10 OF 51 REFERENCES

Consistently large cosmic flows on scales of 100 h−1 Mpc: a challenge for the standard ΛCDM cosmology

- Physics
- 2009

The bulk flow, i.e. the dipole moment of the peculiar velocity field, is a sensitive probe of matter density fluctuations on very large scales. However, the peculiar velocity surveys for which the… Expand

Cosmic flows on 100 h−1 Mpc scales: standardized minimum variance bulk flow, shear and octupole moments

- Physics
- 2009

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,… Expand

Theoretical expectations for bulk flows in large-scale surveys

- Physics
- 1994

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… Expand

Bulk flows from velocity field surveys: A Consistency check

- Physics
- 2006

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 catalogues. We study whether the… Expand

A slight excess of large-scale power from moments of the peculiar velocity field

- Physics
- 2010

ABSTRACT The peculiar motions of galaxies can be used to infer the distribution of matter in theUniverse.It has recently been shown that measurementsof the peculiar velocityﬁeld indicatesan… Expand

The peculiar motions of early-type galaxies in two distant regions — VII. Peculiar velocities and bulk motions

- Physics
- 2000

We present peculiar velocities for 85 clusters of galaxies in two large volumes at distances between 6000 and 15 000 km s−1 in the directions of Hercules–Corona Borealis and Perseus–Pisces–Cetus (the… Expand

Seeking the Local Convergence Depth. V. Tully-Fisher Peculiar Velocities for 52 Abell Clusters

- Physics
- 1999

We have obtained I-band Tully-Fisher (T-F) measurements for 522 late-type galaxies in the fields of 52 rich Abell clusters distributed throughout the sky between ~50 and 200 h-1 Mpc. Here we estimate… Expand

Bulk flows from galaxy luminosities: application to 2MASS redshift survey and forecast for next-generation datasets

- Physics
- 2011

We present a simple method for measuring cosmological bulk flows from large redshift surveys, based on the apparent dimming or brightening of galaxies due to their peculiar motion. It is aimed at… Expand

Bulk motions of flat galaxies on 100-Mpc scales from new data

- Physics
- 2004

We use a new expanded and partially modified sample of 1501 thin edge-on spiral galaxies from the RFGC catalog to analyze the non-Hubble bulk motions of galaxies on the basis of a generalized… Expand

A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications

- Physics
- 2008

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… Expand