Related papers: Detection of a Small Scale Cosmic Background Aniso…
We report a measurement of anisotropy in the cosmic microwave background radiation (CMBR) on 7-22 arcminute scales. Observations of 36 fields near the North Celestial Pole (NCP) were made at 31.7 and 14.5 GHz, using the 5.5-meter and…
We present results from microwave background observations at the Owens Valley Radio Observatory. These observations, at 14.5 and 32 GHz, are designed to detect intrinsic anisotropy on scales of 7'. After point source removal, we detect…
We explore the possibility of detecting the excess of the cosmic radio background (CRB) toward galaxy clusters due to its Compton scattering by electrons of the hot intergalactic gas. When mapping the background fluctuations at frequencies…
We are in motion against the cosmic backdrop. This motion is evidenced by the systematic temperature shift - or dipole anisotropy - observed in the Cosmic Microwave Background radiation (CMB). Because of the Doppler effect, the temperature…
We report on new VLA radio observations performed at 1.4 GHz and 4.8 GHz with unprecedented sensitivity and angular resolution (~1 arcsec) of the cool core cluster A 2626, which is known to possess a radio mini-halo at its center. The most…
If the radio background is coming from cosmological sources, there should be some amount of clustering due to the large scale structure in the universe. Simple models for the expected clustering combined with the recent measurement by…
Previously, [1207.0458] proposed an astrophysical explanation of narrow gamma-ray line-like feature(s) at ~100 GeV from Galactic Center region observed by Fermi/LAT [1205.4700]. The model of [1207.0458] is based on the inverse Compton…
We report the first detection of an inverse Compton X-ray emission, spatially correlated with a very steep spectrum radio source (VSSRS), 0038-096, without any detected optical counterpart, in cluster Abell 85. The ROSAT PSPC data and its…
We report the characterization of bright, compact features in the cosmic microwave background radiation (CMBR) detected during the June 1992 and June 1994 balloon flights of the Medium Scale Anisotropy Measurement (MSAM1-92 and MSAM1-94,…
We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z~1. A compensated spherically symmetric homogeneous dust-filled void with radius \~3*10^2…
We have observed profound variability in the radio flux density of the quasar PKS 0405-385 on timescales of less than an hour; this is unprecedented amongst extragalactic sources. If intrinsic to the source, these variations would imply a…
Using the Cosmic Background Imager, a 13-element interferometer array operating in the 26-36 GHz frequency band, we have observed 40 sq deg of sky in three pairs of fields, each ~ 145 x 165 arcmin, using overlapping pointings (mosaicing).…
We present new X-ray (Chandra) and radio (ATCA) observations of the z=0.09 radio galaxy PKS B1416-493, a member of the southern equivalent of the 3CRR sample. We find the source to be embedded in a previously unrecognized bright kT=4.6 keV…
The origin of the radio emission in radio-quiet quasars (RQQ) is not established yet. We present new VLBA observations at 1.6 and 4.9 GHz of ten RQQ (nine detected), which together with published earlier observations of eight RQQ (five…
The negative evolution found in X--ray clusters of galaxies limits the amount of available hot gas for the inverse Compton scattering of the Cosmic Microwave Background (the Sunyaev--Zel'dovich effect). Using a parametrisation of the X-ray…
We detect anisotropy in the cosmic microwave background (CMB) at degree angular scales and confirm a previous detection reported by Wollack et al. (1993). The root-mean-squared amplitude of the fluctuations is $44^{+13}_{-7} \mu$K. This may…
The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…
Spectral analysis of ROSAT PSPC and ASCA archive data and a recent ROSAT HRI observation of the powerful FRII radio galaxy 3C 219 reveal an absorbed point-like source, coincident with the nucleus, and a non-thermal extended component…
VLA B-configuration snapshots have been obtained at 6cm and 20cm of 43 radio quasars with a range of known galaxy cluster environments. The radio sources are characterised by measures of morphology, flux, and size. These are studied as a…
The theoretical basis for the prediction of anisotropies in the cosmic microwave background is very well developed. Very low amplitude density and temperature perturbations produce small gravitational effects, leading to an anisotropy that…