Results 101 to 110 of about 10,480 (204)

Parallax Effect in Microlensing Events Due to Free-floating Planets

The Astronomical Journal
One of the most important applications of microlensing observations is the detection of free-floating planets (FFPs). The timescale of microlensing due to FFPs ( t _E ) is short (a few days). Discerning the annual parallax effect in observations of these
Parisa Sangtarash, Sedighe Sajadian
doaj   +1 more source

The First Model-independent Upper Bound on Microlensing Signature of the Highest-mass Binary Black Hole Event GW231123

The Astrophysical Journal
The recently discovered gravitational-wave event GW231123 is the most massive binary black hole merger detected to date. The inferred source masses of the event fall within the pair-instability supernova mass gap, where black holes formed directly from ...
Aniruddha Chakraborty, Suvodip Mukherjee
doaj   +1 more source

Binary-lens Microlensing Degeneracy: Impact on Planetary Sensitivity and Mass-ratio Function

The Astronomical Journal
Gravitational microlensing is a unique method for discovering cold planets across a broad mass range. Reliable statistics of the microlensing planets require accurate sensitivity estimates.
Yuxin Shang, Hongjing Yang, Jiyuan Zhang, Shude Mao, Andrew Gould, Weicheng Zang, Qiyue Qian, Jennifer C. Yee   +7 more
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microJAX: A Differentiable Framework for Microlensing Modeling with GPU-accelerated Image-centered Ray Shooting

The Astrophysical Journal
We introduce microJAX , the first fully differentiable implementation of the image-centered ray shooting algorithm for gravitational microlensing. Built on JAX and its XLA just-in-time compiler, microJAX exploits GPU parallelism while providing exact ...
Shota Miyazaki, Hajime Kawahara
doaj   +1 more source

Gravitational microlensing research

, 1997
One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves in spiral galaxies. In the framework of a baryonic scenario the most plausible candidates are brown dwarfs, M-dwarfs or white dwarfs and cold molecular clouds (mainly of $H_2$)
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Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey. IV. Lens Mass and Distance Measurements

The Astronomical Journal
As part of the Galactic Bulge Time Domain Survey (GBTDS), the Nancy Grace Roman Galactic Exoplanet Survey (RGES) will use microlensing to discover cold outer planets and free-floating planets not bound to stars.
Sean K. Terry, Etienne Bachelet, Farzaneh Zohrabi, Himanshu Verma, Alison Crisp, Macy J. Huston, Carissma McGee, Matthew Penny, Natasha S. Abrams, Michael D. Albrow, Jay Anderson, Fatemeh Bagheri, Jean-Philippe Beaulieu, Andrea Bellini, David P. Bennett, Galen Bergsten, T. Dex Bhadra, Aparna Bhattacharya, Ian A. Bond, Valerio Bozza, Christopher Brandon, Sebastiano Calchi Novati, Sean Carey, Jessie Christiansen, William DeRocco, B. Scott Gaudi, Jon Hulberg, Stela Ishitani Silva, Sinclaire E. Jones, Eamonn Kerins, Somayeh Khakpash, Katarzyna Kruszyńska, Casey Lam, Jessica R. Lu, Amber Malpas, Shota Miyazaki, Przemek Mróz, Arjun Murlidhar, David Nataf, Marz Newman, Greg Olmschenk, Radek Poleski, Clément Ranc, Nicholas J. Rattenbury, Krzysztof Rybicki, Vito Saggese, Jennifer Sobeck, Keivan G. Stassun, Alexander P. Stephan, Rachel A. Street, Takahiro Sumi, Daisuke Suzuki, Aikaterini Vandorou, Meet Vyas, Jennifer C. Yee, Weicheng Zang, Keming Zhang, (Roman Galactic Exoplanet Survey Project Infrastructure Team)   +57 more
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The First Model-independent Chromatic Microlensing Search: No Evidence in the Gravitational Wave Catalog of LIGO–Virgo–KAGRA

The Astrophysical Journal
The lensing of gravitational waves (GWs) due to intervening matter distribution in the Universe can lead to chromatic and achromatic signatures in the wave-optics and geometrical-optics limit, respectively.
Aniruddha Chakraborty, Suvodip Mukherjee
doaj   +1 more source

μ-GLANCE: A Novel Technique to Detect Chromatically and Achromatically Lensed Gravitational-wave Signals

The Astrophysical Journal
Gravitational microlensing in the wave-optics (WO) regime occurs when the Schwarzschild radius of a lensing object is comparable to or smaller than the wavelength of incoming gravitational waves (GWs), producing chromatic amplitude and phase modulations.
Aniruddha Chakraborty, Suvodip Mukherjee
doaj   +1 more source

Microlensing Optical Depth, Event Rate, and Limits on Compact Objects in Dark Matter Based on 20 Yr of OGLE Observations of the Small Magellanic Cloud

The Astrophysical Journal Supplement Series
Some previous studies have suggested that massive and intermediate-mass primordial black holes (PBHs) could comprise a substantial fraction of dark matter in the Universe.
Przemek Mróz, Andrzej Udalski, Michał K. Szymański, Igor Soszyński, Paweł Pietrukowicz, Szymon Kozłowski, Radosław Poleski, Jan Skowron, Dorota Skowron, Krzysztof Ulaczyk, Mariusz Gromadzki, Krzysztof Rybicki, Patryk Iwanek, Marcin Wrona, Milena Ratajczak   +14 more
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Introduction to Gravitational Microlensing

, 2008
The basic concepts of gravitational microlensing are introduced. We start with the lens equation, and then derive the image positions and magnifications. The statistical quantities of optical depth and event rate are then described. We finish with a summary and a list of challenges and open questions. A problem set is given for students to practice.
openaire   +2 more sources