Related papers: Deriving accurate peculiar velocities (even at hig…
We present a new method for fitting peculiar velocity models to complete flux limited magnitude-redshifts catalogues, using the luminosity function of the sources as a distance indicator.The method is characterised by its robustness. In…
The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…
Recent measurements of the Hubble constant using type Ia supernovae explicitly correct for their estimated peculiar velocities using the 2M++ reconstruction of the local density field. The amount of uncertainty from this reconstruction…
The measurement of Doppler velocity shifts in spectra is a ubiquitous theme in astronomy, usually handled by computing the cross-correlation of the signals, and finding the location of its maximum. This paper addresses the problem of the…
An attempt to answer the question 'Can we observe galaxies that recede faster than light ?' led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general…
Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent…
We present predictions for redshift-space peculiar velocity statistics in the Lagrangian and Eulerian formulations of the effective field theory (EFT) of large-scale structure. We compute 2-point pairwise velocity statistics up to the…
We propose to use the flux variability of lensed quasar images induced by gravitational microlensing to measure the transverse peculiar velocity of lens galaxies over a wide range of redshift. Microlensing variability is caused by the…
We have made measurements of the Sunyaev-Zel'dovich (SZ) effect in six galaxy clusters at z > 0.2 using the Sunyaev-Zel'dovich Infrared Experiment (SuZIE II) in three frequency bands between 150 and 350 GHz. Simultaneous multi-frequency…
A reconstruction method for recovering the initial conditions of the Universe starting from the present galaxy distribution is presented which guarantees uniqueness of solutions. We show how our method can be used to obtain the peculiar…
We present a proof-of-concept study of a method to estimate the inclination angle of compact high velocity clouds (CHVCs), i.e. the angle between a CHVC's trajectory and the line-of-sight. The inclination angle is derived from the CHVC's…
We consider elliptic variational inequalities generated by obstacle type problems with thin obstacles. For this class of problems, we deduce estimates of the distance (measured in terms of the natural energy norm) between the exact solution…
We study the expansion of the nearby Universe using a sample of Type Ia supernovae at redshifts below 0.08. These supernovae allow peculiar velocities to be measured at unprecedented precision. We have investigated in detail the possibility…
Context: In astronomy, new approaches to process and analyze the exponentially increasing amount of data are inevitable. While classical approaches (e.g. template fitting) are fine for objects of well-known classes, alternative techniques…
Using third-order perturbation theory, we derive a relation between the mean divergence of the peculiar velocity given density and the density itself. Our calculations assume Gaussian initial conditions and are valid for Gaussian filtering…
Hubble's Law, v=HD (recession velocity is proportional to distance), is a theoretical result derived from the Friedmann-Robertson-Walker metric. v=HD applies at least as far as the particle horizon and in principle for all distances. Thus,…
Peculiar velocities are an important probe of the mass distribution in the Universe and the growth rate of structure, directly measuring the effects of gravity on the largest scales and providing a test for theories of gravity. Comparing…
A method for estimating redshifts of galaxy clusters based solely on resolved Sunyaev-Zel'dovich (SZ) images is proposed. Given a high resolution SZ cluster image (with FWHM of approx. 1 arcmin), the method indirectly measures its structure…
We analyze the internal velocity dispersions of a sample of 172 nearby galaxy clusters (z < 0.15), each of which has at least 30 available galaxy redshifts, and spans a large richness range. Cluster membership selection is based on…
We derive explicit and exact expressions for the physical velocity of a free particle comoving with the Hubble flow as measured by a static observer, and for the frequency shift of light emitted by a comoving source and received, again, by…