Related papers: A Parametric Galactic Model toward the Galactic Bu…

Recent results form the James Webb Space Telescope (JWST) report space densities for bright and massive galaxies at z>7 that far exceed expectations of theoretical models of galaxy formation, prompting a revision of our understanding of the…

We determine an absolute calibration of the initial mass function (IMF) of early-type galaxies, by studying a sample of 56 gravitational lenses identified by the SLACS Survey. Under the assumption of standard Navarro, Frenk & White dark…

The stellar initial-mass function (IMF) represents a fundamental quantity in astrophysics and cosmology, describing the mass distribution of stars from low to very-high masses. It is intimately linked to a wide variety of topics, including…

OGLE-2016-BLG-1093 is a planetary microlensing event that is part of the statistical $Spitzer$ microlens parallax sample. The precise measurement of the microlens parallax effect for this event, combined with the measurement of finite…

The stellar initial mass function (IMF) describes the distribution in stellar masses produced from a burst of star formation. For more than fifty years, the implicit assumption underpinning most areas of research involving the IMF has been…

We analyse the effects on the predictions for the microlensing searches toward the Galactic bulge coming from the fact that not all the stars monitored belong to the bulge itself, but that a non--negligible fraction of them actually are in…

I show that by observing microlensing events both astrometrically and photometrically, the Space Interferometry Mission (SIM) can measure the mass function of stellar remnants in the Galactic bulge including white dwarfs, neutron stars, and…

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…

Microlensing is able to reveal multiple body systems located several kilo-parsec away from the Earth. Since it does not require the measurement of light from the lens, microlensing is sensitive to a range of objects from free-floating…

We determine the microlensing event rate distribution, $\Gamma(t_{E})$, that is properly normalized by the first year MACHO group observations (Alcock et al. 1997). By comparing the determined $\Gamma(t_{E})$ with various MF models of lens…

We test whether the universal initial mass function (UIMF) or the integrated galaxial IMF (IGIMF) can be employed to explain the metallicity distribution (MD) of giants in the Galactic bulge. We make use of a single-zone chemical evolution…

The stellar initial mass function (IMF) is thought to be bottom-heavy in the cores of the most massive galaxies, with an excess of low mass stars compared to the Milky Way. However, studies of the kinematics of quiescent galaxies at 2<z<5…

The microlensing probability (optical depth $\tau$) toward the Galactic center carries information about the mass distribution of the Galactic bulge/bar, so can be used to constrain the very uncertain shape parameters of the bar. We find…

We report the discovery of a microlensing planet OGLE-2012-BLG-0950Lb with the planet/host mass ratio of $q \sim 2 \times 10^{-4}$. A long term distortion detected in both MOA and OGLE light curve can be explained by the microlens parallax…

We present the discovery of a Neptune-mass planet orbiting a 0.8 +- 0.3 M_Sun star in the Galactic bulge. The planet manifested itself during the microlensing event MOA 2011-BLG-028/OGLE-2011-BLG-0203 as a low-mass companion to the lens…

We combine VI photometry from OGLE-III with VVV and 2MASS measurements of E(J-K_{s}) to resolve the longstanding problem of the non-standard optical extinction toward the Galactic bulge. We show that the extinction is well-fit by the…

We investigate the impact of combining Gaia astrometry from space with precise, high cadence OGLE photometry from the ground. For the archival event OGLE3-ULENS-PAR-02, which is likely a black hole, we simulate a realistic astrometric…

We present an analysis of Galactic bulge stars from Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) observations of the Stanek window (l,b=[0.25,-2.15]) from two epochs approximately two years apart. This dataset is adjacent to the…

The Stellar Initial Mass Function (IMF) characterizes the mass distribution of newly formed stars in various cosmic environments, serving as a fundamental assumption in astrophysical research. Recent findings challenge the prevalent notion…

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…