Related papers: Variability-selected quasars behind the Small Mage…

We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the SDSS Data Release 3 (~4188 deg^2), we…

We propose a method to distinguish between planetary and stellar companions to stars which present a periodic decrease in brightness, interpreted as a transit. Light curves from a total of 177 stars from the OGLE project were fitted by the…

Given their extremely large distances and small apparent sizes, quasars are generally considered as objects with near-zero parallax and proper motion. However, some special quasars may have abnormal astrometric characteristics, such as…

There are 509 expanding neutral hydrogen shells catalogued in the Small Magellanic Cloud (SMC), all apparently very young, with dynamical ages of a few Myr. To examine their relationship with young stellar objects we cross-correlated the…

A refined sample of 64 variable objects with stellar image structure has been identified in SA 57 to $B \sim 22.5$, over a time baseline of 15 years, sampled at 11 distinct epochs. The photometric data typically have a root-mean-square…

We present 100 multiple cluster candidates selected from the OGLE catalog of star clusters in the Large Magellanic Cloud. Statistical analysis shows that the significant fraction of these objects may constitute physical systems. Coeval ages…

We present the results of an optical spectroscopic survey of 46 heavily obscured quasar candidates. Objects are selected using their mid-infrared (mid-IR) colours and magnitudes from the Wide-Field Infrared Survey Explorer (WISE) and their…

We exploit the spectral archive of the Sloan Digital Sky Survey (SDSS) Data Release 7 to select unusual quasar spectra. The selection method is based on a combination of the power of self-organising maps and the visual inspection of a huge…

We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the expected number of quasars lensed by…

Recently, it was suggested that large concentrations or groups of quasars may trace sites of enhanced matter density at medium and high redshifts analogous to how galaxy clusters trace them in nearby space. We have checked existing quasar…

We report the first search for new star clusters performed using the VISTA near-infrared YJKs Magellanic Clouds survey (VMC) data sets. We chose a pilot field of ~ 0.4 deg^2 located in the South-West of the Small Magelllanic Cloud (SMC)…

Our paper presents new methods for finding and testing of weak periodic variability of stellar objects developed for the purpose of detecting expected regular light variations of magnetic chemically peculiar (mCP) candidates in the Large…

We present the first results from a Chandra survey of the central region of the Small Magellanic Cloud. We detect a total of 122 sources down to a limiting luminosity of ~4.3x10^{33} erg\s (corrected for Galactic N_{H}), which is ~10 times…

We present high signal-to-noise optical spectra for 67 low-redshift (0.1 < z < 0.4) galaxies that lie within close projected distances (5 kpc < rho < 150 kpc) of 38 background UV-bright QSOs. The Keck LRIS and Magellan MagE data presented…

Over the last decade, quasar sample sizes have increased from several thousand to several hundred thousand, thanks mostly to SDSS imaging and spectroscopic surveys. LSST, the next-generation optical imaging survey, will provide hundreds of…

High-redshift quasars are currently the only probes of the growth of supermassive black holes and potential tracers of structure evolution at early cosmic time. Here we present our candidate selection criteria from the Panoramic Survey…

We revisit the subject of Be star candidates towards the Magellanic Clouds, previously studied by the authors using SPM4 proper motions. We obtain GAIA DR2 parallaxes and proper motions for 2357 and 994 LMC and SMC Be candidates,…

We present an analysis of Young Stellar Object (YSO) candidates towards the LDN 1188 molecular cloud. The YSO candidates were selected from the WISE all-sky catalogue, based on a statistical method. We found 601 candidates in the region,…

We present the results of a multi-colour (VIZ) survey for low luminosity (M_B<-23.5) quasars with z~5 using the 12K CCD mosaic camera on CFHT. The survey covers 1.8deg^2 to a limiting magnitude of m_z=22.5(Vega), about two magnitudes…

We present analysis of the large sample of variable red giants from the Large and Small Magellanic Clouds detected during the second phase of the Optical Gravitational Lensing Experiment (OGLE-II) and supplemented with OGLE-III photometry.…