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

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We review recent gravitational microlensing results from the EROS, MACHO, and OGLE collaborations, and present some details of the very latest MACHO results toward the Galactic Bulge. The MACHO collaboration has now discovered in excess of…

Free-floating planets are recently drawing a special interest of the scientific community. Gravitational microlensing is up to now the exclusive method for the investigation of free-floating planets, including their spatial distribution…

Earth and Planetary Astrophysics · Physics 2014-10-16 L. Hamolli , M. Hafizi , A. A. Nucita

The Gaia space telescope allows for unprecedented accuracy for astrometric measurements of stars in the Galaxy. In this work, we explore the sensitivity of Gaia to detect primordial black hole (PBH) dark matter through the distortions that…

Astrophysics of Galaxies · Physics 2023-05-31 Himanshu Verma , Vikram Rentala

AIMS:The aim of this paper is to study the characteristics of the stellar populations and the metallicity distribution in the Galactic bulge. We study the entire stellar population, but also retrieve information using only the red clump…

Astrophysics of Galaxies · Physics 2023-07-19 E. Vanhollebeke , M. A. T. Groenewegen , L. Girardi

We present the distribution of a statistical sample of nearby galaxies in the k-space (k1 ~ log M, k2 ~ log Ie, k3 ~ log M/L). Our study is based on near-IR (H-band: lambda = 1.65 micron) observations, for the first time comprising early-…

Astrophysics · Physics 2009-11-07 D. Pierini , G. Gavazzi , P. Franzetti , M. Scodeggio , A. Boselli

Identifying black holes is essential for comprehending the development of stars and uncovering novel principles of physics. Gravitational microlensing provides an exceptional opportunity to examine an undetectable population of black holes…

We compute the predicted optical depth and duration distribution of microlensing events towards Baade's window in a model composed of a Galactic disk and a bar. The bar model is a self-consistent dynamical model built out of individual…

Astrophysics · Physics 2009-10-22 HongSheng Zhao , David N. Spergel , R. Michael Rich

The optimization and interpretation of microlensing surveys depends on having an accurate model of the Milky Way. However, existing population synthesis Galactic modeling tools often perform poorly in replicating the stellar contents of the…

A wealth of observations recently challenged the notion of a universal stellar initial mass function (IMF) by showing evidences in favour of a variability of this statistical indicator as a function of galaxy properties. I present…

Astrophysics of Galaxies · Physics 2020-06-17 Fabio Fontanot

Red clump giants in the Galactic bulge are approximate standard candles and hence they can be used as distance indicators. We compute the proper motion dispersions of RCG stars in the Galactic bulge using the proper motion catalogue from…

We review recent determinations of the present day and initial mass functions in various components of the Galaxy, disk, spheroid, young and globular clusters. As a general feature, the IMF is well described by a power-law form for $m\ga 1…

Astrophysics · Physics 2008-11-26 Gilles Chabrier

Microlensing is the only known direct method to measure the masses of stars that lack visible companions. In terms of microlensing observables, the mass is given by M=(c^2/4G)\tilde r_E \theta_E and so requires the measurement of both the…

Modern spectroscopic surveys combined with Gaia distances are enabling reliable estimates of fundamental parameters for hundreds of Galactic O-type stars and the full range of spectral types and luminosity classes. Here we provide updated,…

Solar and Stellar Astrophysics · Physics 2025-11-25 G. Holgado , S. Simón-Díaz , A. Herrero

This article summarizes recent work on the luminosity and mass distribution of the Galactic bulge and disk, and on the mass of the Milky Way's dark halo. A new luminosity model consistent with the COBE NIR data and the apparent magnitude…

Astrophysics · Physics 2021-04-28 Ortwin Gerhard

We describe observations carried out by the MOA group of the Galactic Bulge during 2000 that were designed to detect efficiently gravitational microlensing of faint stars in which the magnification is high and/or of short duration. These…

The abundance and narrow magnitude dispersion of Red Clump (RC) stars make them a popular candidate for mapping the morphology of the bulge region of the Milky Way. Using an estimate of the RC's intrinsic luminosity function, we extracted…

Astrophysics of Galaxies · Physics 2023-08-10 Brenna Coleman , Dylan Paterson , Chris Gordon , Oscar Macias , Harrison Ploeg

The MACHO collaboration has been carrying out Difference Image Analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to…

New mass estimates and cumulative mass profiles with Bayesian credible regions (c.r.) for the Milky Way (MW) are found using the Galactic Mass Estimator (GME) code and dwarf galaxy (DG) kinematic data from multiple sources. GME takes a…

Astrophysics of Galaxies · Physics 2022-01-26 Anika Slizewski , Xander Dufresne , Keslen Murdock , Gwendolyn Eadie , Robyn Sanderson , Andrew Wetzel , Mario Juric

We use mock images of $z=0.1$ galaxies in the 100 Mpc EAGLE simulation to establish the differences between the sizes and morphologies inferred from the stellar mass distributions and the optical light distributions. The optical, $r$-band…

Astrophysics of Galaxies · Physics 2021-12-15 Anna de Graaff , James Trayford , Marijn Franx , Matthieu Schaller , Joop Schaye , Arjen van der Wel

We present both the technical overview and main science drivers of the fourth phase of the Optical Gravitational Lensing Experiment (hereafter OGLE-IV). OGLE-IV is currently one of the largest sky variability surveys worldwide, targeting…

Solar and Stellar Astrophysics · Physics 2015-04-24 A. Udalski , M. K. Szymański , G. Szymański