Related papers: WMAP extragalactic point sources as potential Spac…
We have used VLBA fringe visibility data obtained at 15 GHz to examine the compact structure in 250 extragalactic radio sources. For 171 sources in our sample, more than half of the total flux density seen by the VLBA remains unresolved on…
Active Galactic Nuclei (AGN) play a decisive role in galaxy evolution, particularly so when operating in a radiatively inefficient mode, where they launch powerful jets that reshape their surroundings. However, identifying them is…
We describe a new method which achieves high precision Very Long Baseline Interferometry (VLBI) astrometry in observations at millimeter wavelengths. It combines fast frequency-switching observations, to correct for the dominant…
We present a milliarcsecond-resolution radio survey of 17 high-redshift (4 < z < 5.4) blazar candidates observed with the European Very Long Baseline Interferometry (VLBI) Network at 5 GHz. The primary objective of this study was to…
(Abridged) While the major contribution to the Cosmic Microwave Background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower…
The primary goal of the MAP satellite, now in orbit, is to make high fidelity polarization sensitive maps of the full sky in five frequency bands between 20 and 100 GHz. From these maps we will characterize the properties of the cosmic…
We have selected a field from the VLA FIRST Survey which is typical in all aspects except one: it contains a bright, but extremely compact VLBI calibrator - J1159+291. 127 unresolved FIRST sources with $S_{FIRST}\ge 10$ mJy lie within…
Many low-luminosity active galactic nuclei (AGNs) contain a compact radio core which can be observed with high angular resolution using very long baseline interferometry (VLBI). Combining arcsec-scale structural information with…
A review is given on the current status and selected results from large VLBI surveys of compact extragalactic radio sources made between 13 cm and 3 mm wavelengths and covering the entire sky. More than 4200 objects are observed and imaged…
This paper presents the third extension to the Very Large Baseline Array (VLBA) Calibrator Survey, containing 360 new sources not previously observed with very long baseline interferometry (VLBI). The survey, based on three 24 hour VLBA…
GHz-peaked spectrum (GPS) radio sources are thought to be young objects which later evolve into FR-I and FR-II radio galaxies. We have used the Australia Telescope 20GHz (AT20G) survey catalogue to select a uniform sample of GPS sources…
We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…
We observed with the VLBA at 2.3 and 8.6 GHz a complete flux-density limited sample of 482 radio sources with declination >+75 degrees brighter than 200 mJy at 1.4 GHz drawn from the NVSS catalog. 34% of the sources show parsec-scale…
The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are…
We present a full-sky model of polarized Galactic microwave emission based on three years of observations by the Wilkinson Microwave Anisotropy Probe (WMAP) at frequencies from 23 to 94 GHz. The model compares maps of the Stokes Q and U…
We present the final nine-year maps and basic results from the WMAP mission. We provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are…
Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data confirm the ellipticity of anisotropies of Cosmic Microwave Background (CMB) maps, found previously for Boomerang and WMAP 1-year high sensitivity maps. The low noise level of the WMAP…
High-redshift radio sources provide plentiful opportunities for studying the formation and evolution of early galaxies and supermassive black holes. However, the number of known radio-loud active galactic nuclei (AGN) above redshift 4 is…
Precision measurement of the scalar perturbation spectral index, n_s, from the Wilkinson Microwave Anisotropy Probe temperature angular power spectrum requires the subtraction of unresolved point source power. Here we reconsider this issue.…
A short overview is given of the status of research on young extragalactic radio sources. We concentrate on Very Long Baseline Interferometric (VLBI), and space-VLBI results obtained with the VLBI Space Observatory Programme (VSOP). In…