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Related papers: Microlensing near macro-caustics

200 papers

Each strongly lensed image of a quasar behind a lensing galaxy (or galaxy cluster) is composed of a swarm of micro-images. This is a result of microlensing due to stellar-scale substructure in the lens. The presence of microlenses forms a…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Ashish Kumar Meena , Prasenjit Saha

The fraction of quasar's and gamma-ray burst (GRB) afterglows that vary due to microlensing by the stellar populations of intervening elliptical/S0 galaxies is computed by combining the joint distribution of effective microlensing…

Astrophysics · Physics 2009-11-07 J. S. B. Wyithe , E. L. Turner

We consider small-scale spheroidal clusters of weakly interacting massive particles in our Galaxy as non-compact gravitational microlenses and predict the appearance of caustics in the plane of a lensed source. The crossing of these…

Astrophysics · Physics 2010-04-30 M. B. Bogdanov , A. M. Cherepashchuk

We show how observations of multiply-imaged quasars at high redshift can be used as a probe of dark matter clumps (subhalos with masses ~ 10^9 solar masses) within the virialized extent of more massive lensing halos. A large abundance of…

Astrophysics · Physics 2015-06-24 R. Benton Metcalf , Piero Madau

We study three-dimensional microlensing where two lenses are located at different distances along the line of sight. We formulate the lens equation in complex notations and recover several previous results. There are in total either 4 or 6…

Astrophysics of Galaxies · Physics 2015-06-17 Shude Mao , Hans J. Witt , Jin H. An

The current searches for microlensing events towards the galactic bulge can be used to detect planets around the lensing stars. Their effect is a short-term modulation on the smooth lightcurve produced by the main lensing star. Current and…

Astrophysics · Physics 2015-06-24 Joachim Wambsganss

The magnifications of the images in a strong gravitational lens system are sensitive to small mass clumps in the lens potential; this effect has been used to infer the amount of substructure in galaxy dark matter halos. I study the theory…

Astrophysics · Physics 2009-11-07 Charles R. Keeton

Studies of the inner regions of micro-lensed AGN during caustic crossing events have often relied upon the approximation that the magnification near a fold caustic is inversely proportional to the square root of the source-caustic distance.…

Astrophysics of Galaxies · Physics 2019-07-31 Luke Weisenbach , Paul Schechter , Joachim Wambsganss

In the context of this paper, microlenses present as oblate clusters of dark matter structures called massive astrophysical compact halo object(MACHO) in the galactic halo are considered. The NFW density profile [1] is derived from the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Tabib Rayed Hossain , Prabir Kumar Haldar , Mehedi Kalam

We present a quantitative analysis of the effect of microlensing caused by random motion of individual stars in the galaxy which is lensing a background quasar. We calculate a large number of magnification patterns for positions of the…

Astrophysics · Physics 2016-08-30 Joachim Wambsganss , Tomislav Kundic

It has been proposed that the MACHOs in our galaxy could be clumped in globular cluster--like associations or RAMBOs (robust associations of massive baryonic objects) (Moore \& Silk 1995). Here we investigate the effect such clustering has…

Astrophysics · Physics 2015-06-24 R Benton Metcalf , Joseph Silk

We study microlensing of the faint images that form close to the centers of strong gravitational lens galaxies. These central images, which have finally begun to yield to observations, naturally appear in dense stellar fields and may be…

Astrophysics · Physics 2008-11-26 Gregory Dobler , Charles R. Keeton , Joachim Wambsganss

We present a rigorous, detailed study of the generic, quantitative properties of gravitational microlensing near cusp catastrophes. We derive explicit formulas for the total magnification and centroid of the images created for sources…

Astrophysics · Physics 2008-11-26 B. Scott Gaudi , A. O. Petters

Quasar microlensing can be used to constrain important astrophysical properties, such as the accretion disk size and the amount of stars in the lensing galaxy. The associated brightness variations over time, in particular high magnification…

Astrophysics of Galaxies · Physics 2025-09-09 Favio Neira , Timo Anguita , Georgios Vernardos

With the increase in the number of observed gravitational wave (GW) signals, detecting strongly lensed GWs by galaxies has become a real possibility. Lens galaxies also contain microlenses (e.g., stars and black holes), introducing further…

Astrophysics of Galaxies · Physics 2022-10-05 Ashish Kumar Meena , Anuj Mishra , Anupreeta More , Sukanta Bose , Jasjeet Singh Bagla

The strong lensing events that are observed in compact clusters of galaxies can, both statistically and individually, return important clues about the structural properties of the most massive structures in the Universe. Substantial work is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 C. Fedeli , M. Meneghetti , S. Gottloeber , G. Yepes

In the near future, wide field surveys will discover 1000's of new strongly lensed quasars, and these will be monitored with unprecedented cadence by the Legacy Survey of Space and Time (LSST). Many of these will undergo caustic-crossing…

Astrophysics of Galaxies · Physics 2024-07-16 Henry Best , Joshua Fagin , Georgios Vernardos , Matthew O'Dowd

Gravitational lensing describes the bending of the trajectories of light and gravitational waves due to the gravitational potential of a massive object. Strong lensing by galaxies can create multiple images with different overall…

General Relativity and Quantum Cosmology · Physics 2024-02-26 Simon M. C. Yeung , Mark H. Y. Cheung , Joseph A. J. Gais , Otto A. Hannuksela , Tjonnie G. F. Li

While elementary particles are the favored candidate for the elusive dark matter, primordial black holes (PBHs) have also been considered to fill that role. Gravitational microlensing is a very well-suited tool to detect and measure the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-10 Sven Heydenreich , Evencio Mediavilla , Jorge Jiménez-Vicente , Héctor Vives-Arias , Jose A. Muñoz

In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a…

High Energy Astrophysical Phenomena · Physics 2016-04-08 Mihai Tomozeiu , Irshad Mohammed , Manuel Rabold , Prasenjit Saha , Joachim Wambsganss