Related papers: Measuring Omega with Galaxy Streaming Velocities
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)…
Connecting galaxies with their descendants (or progenitors) at different redshifts can yield strong constraints on galaxy evolution. Observational studies have historically selected samples of galaxies using a physical quantity, such as…
By studying the bispectrum of the galaxy distribution in the 2dF galaxy redhsift survey (2dFGRS), we have shown that 2dFGRS galaxies are unbiased tracers of the mass distribution. This allows us the break the degeneracy intrinsic to power…
We report a measurement of the streaming motion of the stars in the Galactic bar with the Red Clump Giants (RCGs) using the data of the Optical Gravitational Lensing Experiment II (OGLE-II). We measure the proper motion of 46,961 stars and…
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…
Peculiar motion introduces systematic variations in the observed luminosity distribution of galaxies. This allows one to constrain the cosmic peculiar velocity field from large galaxy redshift surveys. Using around half a million galaxies…
We present the first cosmological measurement derived from a galaxy density field subject to a `clipping' transformation. By enforcing an upper bound on the galaxy number density field in the Galaxy and Mass Assembly survey (GAMA),…
We present the first determination of the pairwise velocity dispersion of galaxies at different luminosity with the final release of the Two-Degree Field Galaxy Redshift Survey (2dFGRS). Our result surprisingly shows that the random…
We present an analysis of the ENEAR sample of peculiar velocities of elliptical galaxies, obtained with D_n-\sigma distances. We use the velocity correlation function to analyze the statistics of the field-object's velocities, while the…
We investigate the evolution of matter density perturbations and some properties of the peculiar velocity field for a special class of exponential potentials in a scalar field model for quintessence, for which a general exact solution is…
We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions for the abundance of star-forming galaxies…
We present the first determination of the pairwise velocity dispersion (PVD) for galaxies in different luminosity intervals using the final release of the Two-Degree Field Galaxy Redshift Survey (2dFGRS). We have discovered quite…
A magnitude limited sample of nearly 9000 early-type galaxies, in the redshift range 0.01 < z < 0.3, was selected from the Sloan Digital Sky Survey using morphological and spectral criteria. The sample was used to study how early-type…
We present precise constraints on the normalization of the power spectrum of mass fluctuations in the nearby universe, sigma_8, as a function of the mean local matter density, Omega_m. Using the observed local X-ray luminosity function of…
The spatial distribution of galaxies we observed is subject to the given condition that we, human beings are sitting right in a galaxy -- the Milky Way. Thus the ergodicity assumption is questionable in interpretation of the observed galaxy…
The exact nature of the arms of spiral galaxies is still an open question. It has been widely assumed that spiral arms in galaxies with two distinct symmetrical arms are the products of density waves that propagate around the disk, with the…
We have used integral field spectroscopy of a sample of six nearby (z~0.01-0.04) high star-formation rate (SFR~10-40 solar masses per year) galaxies to investigate the relationship between local velocity dispersion and star formation rate…
We propose a new method to estimate the photometric redshift of galaxies by using the full galaxy image in each measured band. This method draws from the latest techniques and advances in machine learning, in particular Deep Neural…
We compile a complete collection of 19 recent (since 2000) measurements of $\Theta_0$, the rotational velocity of the Milky Way at $R_0$ (the radial distance of the Sun from the Galactic center). These measurements use tracers that are…
Recent puzzling observations such as the $H_o$ tension, large-scale anisotropies, and massive disk galaxies at high redshifts have been challenging the standard cosmological model. While one possible explanation is that the standard model…