Related papers: PSCz-1.2 Jy Comparison: A Spherical Harmonics Appr…
We present a new reconstruction of the mass density and the peculiar velocity fields in the nearby universe using recent measurements of Tully-Fisher distances for a sample of late spirals. We find significant differences between our…
(compressed version) We combine the CfA Redshift Survey (CfA2) and the Southern Sky Redshift Survey (SSRS2) to estimate the pairwise velocity dispersion of galaxies $\sig12$ on a scale of $\sim 1 \hmpc$. Both surveys are complete to an…
We measure the anisotropy of the redshift-space power spectrum in the 1.2-Jy and QDOT redshift surveys of IRAS-selected galaxies. On large scales, this anisotropy is caused by coherent peculiar motions, and gravitational instability theory…
The analysis of whole-sky galaxy surveys commonly suffers from the problems of shot-noise and incomplete sky coverage (e.g. at the Zone of Avoidance). The orthogonal set of spherical harmonics is utilized here to expand the observed galaxy…
We present some new results from an ongoing investigation of the anisotropy of the two--point correlation function for optically selected galaxies. We have estimated xi(r_p,pi) from the Perseus-Pisces redshift survey, which is now virtually…
We measure the topology (genus) of isodensity contour surfaces in volume limited subsets of the 1.2 Jy IRAS redshift survey, for smoothing scales $\lambda=4\hmpc$, $7\hmpc$, and $12\hmpc$. At $12\hmpc$, the observed genus curve has a…
Recent progress in the measurement of relative distances to galaxies has been quite substantial, and catalogs of 3000 galaxies with distances are soon to become available. The peculiar {\it velocity} field (deviations from Hubble flow)…
A new method for measuring deviations from axisymmetry in the velocity fields of gas disks is presented. The method is an extension of the method that Franx, van Gorkom and de Zeeuw developed for a single orbit gas ring. The measurement is…
We examine the nature of galaxy clustering in redshift space using a method based on an expansion of the galaxian density field in Spherical Harmonics and linear theory. We derive a compact and self-consistent expression for the distortion…
The peculiar velocity of a mass tracer is on average aligned with the dipole modulation of the surrounding mass density field. We present a first measurement of the correlation between radial peculiar velocities of objects in the…
A re-analysis of the Stokes-parameter spectra obtained of the z=0.692 21 cm absorption line toward 3C 286 shows that our original claimed detection of Zeeman splitting by a line-of-sight magnetic field, B_los = 87 microgauss is incorrect.…
With the largest spectroscopic galaxy survey volume drawn from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), we can extract cosmological constraints from the measurements of redshift and geometric distortions at quasi-linear…
To examine how peculiar velocities can affect the 2-, 3-, and 4-point redshift correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize redshift distortions for four different…
Using the VOID FINDER algorithm we have compiled a catalogue of voids in the IRAS 1.2-Jy sample. The positions of the voids correspond well to underdense regions seen in the IRAS smoothed density map. However, since in our analysis no…
We examine the sky distribution of radio galaxies in the NRAO VLA Sky Survey (NVSS) and the Rapid ASKAP Continuum Survey (RACS). Analyses of these samples have reported tension between their inferred dipoles and the kinematic dipole of the…
Utilizing structure constants, we present a version of the Misiolek criterion for identifying conjugate points. We propose an approach that enables us to locate these points along solutions of the quasi-geostrophic equations on the sphere…
We discuss cosmological inference from galaxy surveys at low and high redshifts. Studies of optical and IRAS redshift surveys with median redshift ${\bar z} \sim 0.02$ yield measurements of the density parameter $\Omega$ and the…
Recent cosmic shear studies have reported discrepancies of up to $1\sigma$ on the parameter ${S_{8}=\sigma_{8}\sqrt{\Omega_{\rm m}/0.3}}$ between the analysis of shear power spectra and two-point correlation functions, derived from the same…
We report a highly significant ($>10\sigma$) spatial correlation between galaxies with $S_{350\mu\rm m}\ge 30\,$mJy detected in the equatorial fields of the \textsl{Herschel} Astrophysical Terahertz Large Area Survey (H-ATLAS) with…
We test the hypothesis that the velocity field derived from Tully-Fisher measurements of spiral galaxies, and that derived independently from Dn-sigma measurements of ellipticals and S0s, are noisy versions of the same underlying velocity…