相关论文: Cross-correlation between X-ray and optical/near-i…

We compute the two-point angular correlation function and number-magnitude relation of Hubble Deep Field sources in order to assess their nature. We find that the correlation peaks between 0.25 arcsec and 0.4 arcsec with amplitude of 2 or…

The cross-correlation between fluctuations in the electron scattering optical depth $\tau_{\rm es}$ as probed by future Cosmic Microwave Background (CMB) experiments, and fluctuations in the 21cm differential brightness temperature $\Delta…

Cosmic infrared background fluctuations may contain measurable contribution from objects inaccessible to current telescopic studies, such as the first stars and other luminous objects in the first Gyr of the Universe's evolution. In an…

Cosmic magnification is due to the weak gravitational lensing of sources in the distant Universe by foreground large-scale structure leading to coherent changes in the observed number density of the background sources. Depending on the…

With a high spatial resolution imaging instrument such as the Chandra/ACIS, one can confidently identify an X-ray source with only a few detected counts. The detection threshold of such sources, however, varies strongly across the…

In this paper we investigate the properties of low X-ray-to-optical flux ratio sources detected in a wide area (2.5deg^2) shallow (f(0.5-8keV)~10e-14cgs) XMM-Newton survey. We find a total of 26 sources (5% of the total X-ray selected…

This paper is devoted to studying the CIB through its correlation properties. We studied the limits on CIB anisotropy in the near IR (1.25, 2.2, and 3.5 \um, or $J,\;K,\;L$) bands at a scale of 0.7\deg\ using the COBE\footnote{ The National…

We use both time-domain and Fourier techniques to study the correlated optical and X-rays variability in the black hole X-ray nova XTE J1118+480. Its X-ray timing properties, such as the shape of the X-ray power spectrum and…

The recent deep X-ray surveys at both soft (0.5--2 keV) and hard (2--10 keV) energies have greatly extended our knowledge of the X-ray source density and spectral shapes at relatively faint fluxes adding further evidence on the fact that…

We report on the result of an extensive search for X-ray counterparts to Gamma Ray Bursts (GRB) using data acquired with the Imaging Proportional Counter (IPC) on-board the Einstein Observatory. We examine background sky fields from all…

The narrow-line quasar PHL 1092 was observed by XMM-Newton at two epochs separated by nearly thirty months. Timing analyses confirm the extreme variability observed during previous X-ray missions. A measurement of the radiative efficiency…

Hard X-ray selection is the most efficient way to discriminate between accretion-powered sources, such as AGN, from sources dominated by starlight. Hard X-rays are also less affected than other bands by obscuration. We have then carried out…

In an attempt to constrain and understand the emission mechanism of gamma rays, we perform a cross-correlation analysis of 15 blazars using light curves in millimetre, optical and gamma rays. We use discrete correlation function and…

The angular cross-correlation between two galaxy samples separated in redshift is shown to be a useful measure of weak lensing by large-scale structure. Angular correlations in faint galaxies arise due to spatial clustering of the galaxies…

We use Spitzer/IRAC deep exposure data covering two significantly larger than before sky areas to construct maps suitable for evaluating source-subtracted fluctuations in the cosmic infrared background (CIB). The maps are constructed using…

The cosmic infrared background from galaxies should have a minimum fluctuation of the order of 10\% on angular scales probed by the DIRBE (Diffuse Infrared Background Experiment) on board COBE (Cosmic Background Explorer). We present the…

By comparing the ratio of flux densities in the X-ray and UV wavebands by way of the spectral optical-X-Ray index, $\alpha_{ox}$, we explore the relation between the emissions in the respective wavebands for a number of ULXs with known…

We show that Compton scattering by electrons of the hot intergalactic gas in galaxy clusters should lead to peculiar distortions of the cosmic background X-ray and soft gamma-ray radiation - an increase in its brightness at E<60-100 keV and…

The cosmic infrared background (CIB) radiation is the cosmic repository for energy release throughout the history of the universe. Using the all-sky data from the COBE DIRBE instrument at wavelengths 1.25 - 100 mic we attempt to measure the…

We present the first analysis of large-scale clustering from the Spitzer Wide-area InfraRed Extragalactic legacy survey: SWIRE. We compute the angular correlation function of galaxies selected to have 3.6 micron fluxes brighter than 32 muJy…