Related papers: Galaxy-Quasar correlations between APM galaxies an…
We cross-correlate APM and SDSS galaxies with background QSOs from the 2dF QSO Redshift Survey, and detect a significant (2.8sigma) anti-correlation. The lack of a signal between 2dF stars and our galaxy samples suggests the…
A thorough study of QSO-galaxy correlations has been done on a region close to the North Galactic Pole using a complete subsample of the optically selected CFHT/MMT QSO survey and the galaxy catalog of Odewahn and Aldering (1995). Although…
We detect a positive angular correlation between bright, high-redshift QSOs and foreground galaxies. The QSOs are taken from the optically selected LBQS Catalogue, while the galaxies are from the APM Survey. The correlation amplitude is…
We have carried out an investigation of the galaxy environments of low redshift ($z<0.3$) QSOs by cross-correlating the positions on the sky of X-ray-selected QSOs/AGN identified in the {\it Einstein} Medium Sensitivity Survey (EMSS) with…
We find angular correlations between high redshift radio selected QSOs from the 1 Jy Catalog and APM galaxies on ~1 degree scales. We demonstrate that observed correlations are qualitatively consistant with a gravitational lensing…
We cross-correlate QSOs from the 2dF Survey with galaxy groups. The galaxy samples are limited to B < 20.5. We use an objective algorithm to detect galaxy groups. A 3sigma anti-correlation is observed between QSOs and galaxy groups. This…
Several recent studies show that bright, intermediate and high redshift optically and radio selected QSOs are positively correlated with nearby galaxies on a range of angular scales up to a degree. Obscuration by unevenly distributed…
We report a detection of galaxy-QSO cross-correlation w_GQ in the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR) over 0.2-30 arc-minute scales. We cross-correlate galaxy samples of different mean depths r'=19-22 (z_G =0.15-0.35)…
We have studied the distribution of $B_J<20.5$ galaxies from the ROE/NRL COSMOS/UKST catalogue around two samples of $z>0.3$ QSOs with similar redshift distributions. The first sample is formed by 144 radio-loud QSOs from the Parkes…
Gravitational lensing predicts an enhancement of the density of bright, distant QSOs around foreground galaxies. We measure this QSO-galaxy correlation w_qg for two complete samples of radio-loud quasars, the southern 1Jy and Half-Jansky…
We report the detection of a cross-correlation signal between {\it Fermi} Large Area Telescope diffuse gamma-ray maps and catalogs of clusters. In our analysis, we considered three different catalogs: WHL12, redMaPPer and PlanckSZ. They all…
We simulated both the matter and light (galaxy) distributions in a wedge of the universe and calculated the gravitational lensing magnification caused by the mass along the line of sight of galaxies and galaxy groups identified in sky…
We report the identification of a positive cross-correlation signal between the unresolved $\gamma$-ray emission, measured by the \emph{Fermi} Large Area Telescope, and four different galaxy cluster catalogues. The selected catalogues peak…
In this paper we present results of an analysis of radio-quiet QSO environments. The aim is to determine the relation between QSOs and galaxies as a function of redshift. We cross-correlate a sample of ~150 QSOs from optically and X-ray…
We examine the relationship between galaxies and the intergalactic medium at z < 1 using a group of three closely spaced background QSOs with z_em ~1 observed with the Hubble Space Telescope. Using a new grouping algorithm, we identify…
The lensing of background QSOs by foreground galaxies is a powerful probe of the mass density of the Universe and the power spectrum of mass clustering. However, the 2dF QSO survey suggested that a strong anticorrelation effect at g<21 was…
We present predictions for the galaxy-galaxy lensing profile from the EAGLE hydrodynamical cosmological simulation at redshift z=0.18, in the spatial range 0.02 < R/(Mpc/h) < 2, and for five logarithmically equi-spaced stellar mass bins in…
We examine the clustering of galaxies around a sample of 20 luminous low redshift (z<0.30) quasars observed with the Wide Field Camera-2 on the Hubble Space Telescope. The HST resolution makes possible galaxy identification brighter than…
Several measurements of QSO-galaxy correlations have reported signals much larger than predictions of magnification by large-scale structure. We find that the expected signal depends stronly on the properties of the foreground galaxy…
We describe the construction of catalogues of galaxy clusters from the APM Galaxy survey using an automated algorithm based on Abell-like selection criteria. We investigate the effects of varying several parameters in our selection…