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Related papers: Galactic Bulge Microlensing Events from the MACHO …

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Experiments are looking for diffuse brown dwarfs in the dark galactic halo through the gravitational lens effect. If brown dwarfs are clumped in dark clusters, the event rate is not changed, but events are spatially clustered, and stars…

Astrophysics · Physics 2007-05-23 Alain Bouquet , Jean Kaplan , Jean-Manuel Verschaeve

Hundreds of gravitational microlensing events have now been detected towards the Galactic bulge, with many more to come. The detection of fine structure in these events has been theorized to be an excellent way to discover extra-solar…

Astrophysics · Physics 2010-04-06 Kim Griest , Neda Safizadeh

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

The MACHO Project monitors millions of stars in the Large Magellanic Cloud, the Small Magellanic Cloud and the bulge of the Milky Way searching for the gravitational microlensing signature of baryonic dark matter. This Project has yielded…

We describe the results of a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the Vatican Advanced Technology…

Astrophysics · Physics 2009-10-28 Arlin P. S. Crotts , Austin B. Tomaney

Most stellar remnants so far have been found in binary systems, where they interact with matter from their companions. Isolated neutron stars and black holes are difficult to find as they are dark, yet they are predicted to exist in our…

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2007-05-23 Philippe Jetzer

A high optical depth to gravitational microlensing towards the galactic bulge is consistent with current models of the galactic bar. The low optical depth towards the LMC can probably be accounted for by the ordinary stars in our galaxy and…

Astrophysics · Physics 2016-08-30 Bohdan Paczynski

We present the PLANET photometric data set for \ob14, a high magnification ($A_{\rm max}\sim 16$) event alerted by the OGLE collaboration toward the Galactic bulge in 1998. The PLANET data set consists a total of 461 I-band and 139 $V-$band…

We suggest a new component of the Milky Way galaxy that can account for both the optical depth and the event durations obtained by the MACHO microlensing survey toward the Large Magellanic Cloud. This component is consistent with recent…

Astrophysics · Physics 2007-05-23 Evalyn I. Gates , Geza Gyuk

The MACHO collaboration reports on the analysis of our first year LMC data, 9.5 million light curves with an average of 235 observations each. Automated selection procedures give 3 events consistent with microlensing. We evaluate our…

MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that objects (dubbed MACHOs) with masses in the range $10^{-6}M_\odot < M \simlt 100…

Astrophysics · Physics 2009-10-22 D. P. Bennett

Microlensing maps -- that is, contours of equal numbers of events per $10^6$ source stars -- are provided for the inner Galaxy under two alternative hypotheses : (1) the bulge is an oblate axisymmetric spheroid or (2) the bulge is a prolate…

Astrophysics · Physics 2009-10-22 N. W. Evans

We present the analysis of a binary microlensing event KMT-2016-BLG-2052, for which the lensing-induced brightening of the source star lasted for 2 seasons. We determine the lens mass from the combined measurements of the microlens parallax…

(Abridged) A close scrutiny of the microlensing results towards the Magellanic clouds reveals that the stars within the Magellanic clouds are major contributors as lenses, and the contribution of MACHOs to dark matter is 0 to 5%. The…

Astrophysics · Physics 2007-05-23 Kailash C. Sahu

We present the details of the Bayesian analysis on the planetary microlensing event MOA-2016-BLG-227, whose excess flux is likely due to a source/lens companion or an unrelated ambient star, as well as of the assumed prior distributions.…

Earth and Planetary Astrophysics · Physics 2020-05-27 Naoki Koshimoto , David P. Bennett , Daisuke Suzuki

We use detailed numerical simulations and theoretical estimates to show that, if confirmed, the unusually brief microlensing events observed by Sahu et al. (2001) in the field of the globular cluster M22 might be explained as a result of…

Astrophysics · Physics 2009-11-07 R. de la Fuente Marcos , C. de la Fuente Marcos

We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-source effects, and the microlens parallaxes are derived from…

Solar and Stellar Astrophysics · Physics 2020-03-04 Weicheng Zang , Yossi Shvartzvald , Tianshu Wang , Andrzej Udalski , Chung-Uk Lee , Takahiro Sumi , Jesper Skottfelt , Shun-Sheng Li , Shude Mao , Wei Zhu , Jennifer C. Yee , Sebastiano Calchi Novati , Charles A. Beichman , Geoffery Bryden , Sean Carey , B. Scott Gaudi , Calen B. Henderson , Przemek Mróz , Jan Skowron , Radoslaw Poleski , Michał K. Szymański , Igor Soszyński , Paweł Pietrukowicz , Szymon Kozłowski , Krzysztof Ulaczyk , Krzysztof A. Rybicki , Patryk Iwanek , Etienne Bachelet , Grant Christie , Jonathan Green , Steve Hennerley , Dan Maoz , Tim Natusch , Richard W. Pogge , Rachel A. Street , Yiannis Tsapras , Michael D. Albrow , Sun-Ju Chung , Andrew Gould , Cheongho Han , Kyu-Ha Hwang , Youn Kil Jung , Yoon-Hyun Ryu , In-Gu Shin , Sang-Mok Cha , Dong-Jin Kim , Hyoun-Woo Kim , Seung-Lee Kim , Dong-Joo Lee , Yongseok Lee , Byeong-Gon Park , Richard W. Pogge , Ian A. Bond , Fumio be , Richard Barry , David P. Bennett , Aparna Bhattacharya , Martin Donachie , Akihiko Fukui , Yuki Hirao , Yoshitaka Itow , Iona Kondo , Naoki Koshimoto , Man Cheung Alex Li , Yutaka Matsubara , Yasushi Muraki , Shota Miyazaki , Masayuki Nagakane , Clément Ranc , Nicholas J. Rattenbury , Haruno Suematsu , Denis J. Sullivan , Daisuke Suzuki , Paul J. Tristram , Atsunori Yonehara , Martin Dominik , Markus Hundertmark , Uffe G. Jørgensen , Sohrab Rahvar , Sedighe Sajadian , Colin Snodgrass , Valerio Bozza , Martin J. Burgdorf , Daniel F. Evans , Roberto Figuera Jaimes , Yuri I. Fujii , Luigi Mancini , Penelope Longa-Peña , hristiane Helling , Nuno Peixinho , Markus Rabus , John Southworth , Eduardo Unda-Sanzana , Carolina von Essen