相关论文: Line of sight depth of the Large and Small Magella…

I demonstrate that the two unexpected results in the local Universe: 1) anomalous intrinsic (V-I)_0 colors of the clump giants and RR Lyrae stars in the Galactic center, and 2) very short distances to the Magellanic Clouds (LMC, SMC) as…

Aiming at providing a firm mean distance estimate to the Small Magellanic Cloud (SMC), and thus to place it within the internally consistent Local Group distance framework we recently established, we compiled the current-largest database of…

Four microlensing collaborations are presently searching for compact matter in the Galaxy and all have detected possible candidates. Using the detection efficiencies recently published by the MACHO and OGLE collaborations, we present…

We examine the morphology of the color-magnitude diagram (CMD) for core helium-burning (red clump) stars to test the recent suggestion by Zaritsky & Lin (1997) that an extension of the red clump in the Large Magellanic Cloud (LMC) toward…

(Abridged version): The optical depth is widely used in Galactic microlensing studies as a means to determine the density of MACHOs, since in theory it depends only upon their spatial distribution and is therefore less model-dependent than…

The Galactic bulge and bar are critical to our understanding of the Milky Way. However, due to the lack of reliable stellar distances, the structure and kinematics of the bulge/bar beyond the Galactic center have remained largely…

We estimate the optical depth to self-lensing by stars in the Galactic bulge using the HST star counts of Holtzman et al and Zoccali et al as extrapolated by Gould into the brown-dwarf and remnant regimes and deprojected along the line of…

(Abridged) We analyze the UBVI color-magnitude diagrams towards the Galactic bulge in a relatively low-reddening region of Baade's Window. The dereddened red giant branch is very wide [~1.0 mag in (U-B)_0 and ~0.4 mag in (B-V)_0 and…

We model the split red clump of the Galactic bulge in OGLE-III photometry, and compare the results to predictions from two N-body models. Our analysis yields precise maps of the brightness of the two red clumps, the fraction of stars in the…

The new data for Cepheids and RR Lyrae stars of the Optical Gravitational Lensing Experiment (OGLE-III) survey allow us to study the three-dimensional distribution of stars corresponding to young (a few tens to a few hundreds of millions of…

We present an update of results from the search for microlensing towards the Large Magellanic Cloud (LMC) by EROS (Experience de Recherche d'Objets Sombres). We have now monitored 25 million stars over three years. Because of the small…

The presence of a diffuse stellar component in galaxy clusters has been established by a number of observational works in recent years. In this contribution I summarize our results (Zibetti et al. 2005) obtained by stacking SDSS images of…

We provide a homogeneous set of structural parameters of 83 star clusters located at the periphery of the Small Magellanic Cloud (SMC) and the Large Magellanic Cloud (LMC). The clusters' stellar density and surface brightness profiles were…

We present a detailed investigation of the Large Magellanic Cloud (LMC) disk using classical Cepheids. Our analysis is based on optical (I,V; OGLE-IV), near-infrared (NIR: J,H,Ks) and mid-infrared (MIR: w1; WISE) mean magnitudes. By…

We derive general expressions for the LMC velocity field which we fit to kinematical data for 1041 carbon stars. We demonstrate that all previous studies of LMC kinematics have made unnecessary over-simplifications that have led to…

We present the analysis of the first two years of the OGLE search for gravitational lenses towards the Galactic bulge. We detected 9 microlensing events in an algorithmic search of $ \sim 10^8 $ measurements of $ \sim 10^6 $ stars. The…

We examine the three-dimensional structure and dust extinction properties in a ~ 200 pc $\times$ 100 pc region in the southwest bar of the Small Magellanic Cloud (SMC). We model a deep Hubble Space Telescope optical color-magnitude diagram…

We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediate resolution spectra and infrared images were obtained with FORS1 at the ESO VLT and with the…

Using 7 years of MACHO survey data, we present a new determination of the optical depth to microlensing towards the Galactic bulge. We select the sample of 62 microlensing events (60 unique) on clump giant sources and perform a detailed…

We present Washington C, T1 CCD photometry of 21 fields located in the northern part of the Large Magellanic Cloud (LMC), and spread over a region of more than 2.52 degrees approximately 6 degrees from the bar. The surveyed areas were…