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Related papers: Microlensing optical depth toward the Galactic Bul…

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We completed the search for microlensing events in the zero latitude area of the Galactic bulge using the VVV Survey near-IR data obtained between 2010 and 2015. We have now a total sample of N = 630 events Using the near-IR Color-Magnitude…

Astrophysics of Galaxies · Physics 2018-09-26 María Gabriela Navarro , Dante Minniti , Rodrigo Contreras Ramos

We developed a parametric Galactic model toward the Galactic bulge by fitting to spatial distributions of the Gaia DR2 disk velocity, VVV proper motion, BRAVA radial velocity, OGLE-III red clump star count, and OGLE-IV star count and…

Astrophysics of Galaxies · Physics 2021-08-25 Naoki Koshimoto , Junichi Baba , David P. Bennett

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

Astrophysics · Physics 2009-11-13 Martin C. Smith , Przemyslaw Wozniak , Shude Mao , Takahiro Sumi

Galactic microlensing datasets now comprise in excess of $10^4$ events, and with the advent of next generation microlensing surveys that may be undertaken with facilities such as the Rubin Observatory (formerly LSST) and Roman Space…

Earth and Planetary Astrophysics · Physics 2020-09-30 David Specht , Eamonn Kerins , Supachai Awiphan , Annie C. Robin

We analyze the mean luminosity of three samples of field RRab Lyr stars observed in the course of the OGLE microlensing experiment: 73 stars from the Galactic bulge and 110 and 128 stars from selected fields in the LMC and SMC,…

Astrophysics · Physics 2007-05-23 A. Udalski

We present PLANET observations of OGLE-1999-BUL-23, a binary-lens microlensing event towards the Galactic bulge. PLANET observations in the I and V bands cover the event from just before the first caustic crossing until the end of the…

We present detailed maps of the microlensing optical depth and event density over an area of 195 sq. deg towards the Galactic bulge. The maps are computed from synthetic stellar catalogues generated from the Besancon Galaxy Model, which…

Astrophysics · Physics 2015-05-13 E. Kerins , A. C. Robin , D. J. Marshall

We measure the red giant branch bump (RGBB) of the Galactic bulge, the most metal-rich RGBB ever detected. The RGBB luminosity functions peaks at the expected brightness, but its number density is very low relative to Galactic globular…

Astrophysics of Galaxies · Physics 2015-05-20 D. M. Nataf , A. Udalski , A. Gould , M. H. Pinsonneault

We describe a real-time spectroscopic program to observe bright gravitational microlensing events toward the Galactic Bulge. The program is carried out using the NTT at ESO. We present the preliminary analysis of the microlensing events we…

Astrophysics · Physics 2007-05-23 D. Lennon , S. Mao , J. Reetz , T. Gehren , L. Yan , A. Renzini

In this fourth part of the series presenting the Optical Gravitational Lensing Experiment (OGLE) microlensing studies of the dark matter halo compact objects (MACHOs) we describe results of the OGLE-III monitoring of the Small Magellanic…

We report a measurement of the streaming motion of the stars in the Galactic bar with the Red Clump Giants (RCGs) using the data of the Optical Gravitational Lensing Experiment II (OGLE-II). We measure the proper motion of 46,961 stars and…

Astrophysics · Physics 2009-11-07 T. Sumi , L. Eyer , P. R. Wozniak

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

Photometry of the Galactic bulge, collected during the OGLE-II microlensing search, indicates high and non-uniform interstellar extinction toward the observed fields. We use the mean I-band magnitude and V-I color of red clump stars as a…

Astrophysics · Physics 2008-11-26 A. Udalski

Red clump giant stars can be used as distance indicators to trace the mass distribution of the Galactic bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration database to constrain analytic tri-axial models…

Astrophysics · Physics 2009-06-23 Nicholas J. Rattenbury , Shude Mao , Takahiro Sumi , Martin C. Smith

We present a study of the luminosity density distribution of the Galactic bar using number counts of red clump giants (RCGs) from the OGLE-III survey. The data were recently published by Nataf et al. (2013) for 9019 fields towards the bulge…

Astrophysics of Galaxies · Physics 2013-09-24 Liang Cao , Shude Mao , David Nataf , Nicholas J. Rattenbury , Andrew Gould

We present a statistical assessment of both, observed and reported, photometric uncertainties in the OGLE-IV Galactic bulge microlensing survey data. This dataset is widely used for the detection of variable stars, transient objects,…

Instrumentation and Methods for Astrophysics · Physics 2016-04-08 J. Skowron , A. Udalski , S. Kozłowski , M. K. Szymański , P. Mróz , Ł. Wyrzykowski , R. Poleski , P. Pietrukowicz , K. Ulaczyk , M. Pawlak , I. Soszyński

The apparently repeating microlensing event OGLE-2003-BLG-095 is analyzed. Data were obtained from the OGLE Internet archive and exist in the public domain. The source is relatively bright, with an unmagnified (but possibly blended)…

Astrophysics · Physics 2007-05-23 Matthew J. Collinge

We investigate the possibility of determining whether microlensing objects towards the Large Magellanic Cloud (LMC) are in a Galactic thick disc, or are in a Galactic halo, by using parallax measurements with an Earth-radius scale baseline.…

Astrophysics · Physics 2009-11-07 T. Sumi , Y. Kan-ya

We search for microlensing events in fields along the Galactic minor axis, ranging from the Galactic center to -3.7<b< 3.9 deg., using the VVV survey near-IR photometry. The new search is made across VVV tiles b291, b305, b319, b347, b361…

Solar and Stellar Astrophysics · Physics 2020-02-05 Maria Gabriela Navarro , Dante Minniti , Joyce Pullen , Rodrigo Contreras Ramos

We analyze three years (1998-2000) of OGLE observations of microlensing events to place limits on the abundance of planets with a planet-to-star mass ratio $q=10^{-3}$ at distances $\sim 1-4$AU from their host stars, i.e. `cool Jupiters'.…

Astrophysics · Physics 2009-11-07 Yiannis Tsapras , Keith Horne , Stephen Kane , Richard Carson