相关论文: Confusion errors in astrometry and counterpart ass…

Equations to investigate fluctuations in cosmic X-ray background radiation due to point-like sources at high-redshift are formulated in a systematic way. The angular power spectrum of X-ray background fluctuations is investigated from…

Faint submillimeter sources detected with the Submillimeter Common-User Bolometer Array on the James Clerk Maxwell Telescope have faced an identification problem due to the telescope's broad beam profile. Here we propose a new method to…

Self-calibrating and dual-slope measurements have been used in the field of diffuse optics for robust assessment of absolute values or temporal changes in the optical properties of highly scattering media and biological tissue. These…

We are investigating to what extent one can use a P(D) analysis to extract number counts of unclustered sources from maps of the far infrared background. Currently available such maps, and those expected to emerge in near future are…

Polarized foregrounds are going to be a serious challenge for detecting CMB cosmological B-modes. Both diffuse Galactic emission and extragalactic sources contribute significantly to the power spectrum on large angular scales. At low…

The location of a galaxy cluster's centroid is typically derived from observations of the galactic and/or gas component of the cluster, but these typically deviate from the true centre. This can produce bias when observations are combined…

The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color…

We perform a systematic analysis of the effects of photometric redshift uncertainties on weak lensing tomography. We describe the photo-z distribution with a bias and Gaussian scatter that are allowed to vary arbitrarily between intervals…

The limiting factor of the accuracy of WFPC2 photometry is the CTE loss, which has increased to the level of 50% or more for faint stars at the top of the chips. I describe recent work on characterizing this effect, and provide improved…

If a gravitational microlensing event is caused by a widely separated binary lens and the source approaches both lens components, the source flux is successively magnified by the individual lenses: double microlensing events. If events are…

As the Universe expands, the redshift of distant sources changes with time. Here we discuss gravitational lensing phenomena that are consequence of the redshift drift between lensed source, gravitational lens, and observer. When the source…

We measure the astrometric shifts of the light centroids for the microlensing events in the OGLE-1 database. Of the 15 consistently detected events, 7 had significant shifts which we were able to measure with a fair degree of confidence.…

We quantify the uncertainty in weak lensing mass estimates of clusters of galaxies, caused by distant (uncorrelated) large scale structure along the line of sight. We find that the effect is fairly small for deep observations (20<R<26) of…

Spatial confounding is a fundamental issue in spatial regression models which arises because spatial random effects, included to approximate unmeasured spatial variation, are typically not independent of covariates in the model. This can…

Recently measured straylight PSFs in Hinode/SOT make granulation contrast in observed data and synthetic MHD data consistent. Data from earthbound telescopes also need accurate correction for straylight and fixed optical aberrations. We aim…

If the background universe is observed through a significant amount of diffusely distributed foreground dust, then studies at optical wavelengths may be severely biased. Previous studies investigating effects of foreground dust on…

We investigate what we can learn about galaxy formation and evolution from the data which will be obtained by the forthcoming large submillimeter/millimeter facilities, mainly by the Atacama Submillimeter Telescope Experiment (ASTE) and the…

Astrometric observations of microlensing events can be used to obtain important information about lenses. During these events, the shift of the position of the multiple image centroid with respect to the source star location can be…

In an investigation of the cause of the cosmic microwave background decrement in the field of the z = 3.8 quasar pair PC1643+4631, we have carried out a study to photometrically estimate the redshifts of galaxies in deep multi-colour…

Spectroastrometry is a technique which has the potential to resolve flux distributions on scales of milliarcseconds. In this study, we examine the application of spectroastrometry to binary point sources which are spatially unresolved due…