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Related papers: Quasar Microlensing: when compact masses mimic smo…

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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

Microlensing near macro-caustics is a complex phenomenon in which swarms of micro-images produced by micro-caustics form on both sides of a macro-critical curve. Recent discoveries of highly magnified images of individual stars in massive…

Astrophysics of Galaxies · Physics 2024-04-15 Luke Weisenbach , Timo Anguita , Jordi Miralda-Escudé , Masamune Oguri , Prasenjit Saha , Paul L. Schechter

The idea that dark matter can be made of intermediate-mass primordial black holes in the $10M_\odot \lesssim M \lesssim 200M_\odot$ range has recently been reconsidered, particularly in the light of the detection of gravitational waves by…

Astrophysics of Galaxies · Physics 2017-02-22 E. Mediavilla , J. JimÉnez-Vicente , J. A. MuÑoz , H. Vives-Arias , J. CalderÓn-Infante

It has been conjectured that the distribution of magnifications of a point source microlensed by a population of intervening point masses is independent of its mass spectrum. We present gedanken experiments that cast doubt on this…

Astrophysics · Physics 2009-11-10 Paul L. Schechter , Joachim Wambsganss , Geraint F. Lewis

Gravitational microlensing is a powerful tool for probing the physical properties of quasar accretion disks and properties of the lens galaxy such as its dark matter fraction and mean stellar mass. Unfortunately the number of lensed quasars…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-19 Ana M. Mosquera , Christopher S. Kochanek

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

The first investigations of the response of the microlensing magnification pattern (at an optical depth of order unity) to the mass function of the microlenses found that the resulting statistics depend only on the mean microlens mass <m>.…

Astrophysics · Physics 2009-10-31 J. S. B. Wyithe , E. L. Turner

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

A small fraction of all quasars are strongly lensed and multiply imaged, with usually a galaxy acting as the main lens. Some, maybe all of these quasars are also affected by microlensing, the effects of stellar mass objects in the lensing…

Astrophysics · Physics 2009-11-10 Marie Treyer , Joachim Wambsganss

We investigate gravitational microlensing signals produced by a spatially extended object transiting in front of a finite-sized source star. The most interesting features arise for lens and source sizes comparable to the Einstein radius of…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 Djuna Croon , David McKeen , Nirmal Raj , Zihui Wang

We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Such an effect could be caused by stellar mass objects (SMO) located in a bulge or/and in a halo of this quasar as well as at cosmological…

Astrophysics · Physics 2007-05-23 A. F. Zakharov , L. C. Popovic , P. Jovanovic

Microlensing studies of quasars can reveal dark matter lumps over a broad mass spectrum; we highlight the importance of monitoring quasars which are seen through the halos of low-redshift galaxies. For these configurations microlensing by…

Astrophysics · Physics 2009-10-30 Mark A. Walker

Dark matter may be in the form of non-baryonic structures such as compact subhalos and boson stars. Structures weighing between asteroid and solar masses may be discovered via gravitational microlensing, an astronomical probe that has in…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Djuna Croon , David McKeen , Nirmal Raj

We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…

Astrophysics · Physics 2009-11-07 Eric Agol

It has been revealed using microlensing that a considerable part, possibly more than half, of the dark matter in the halo of our Galaxy consists of objects with a mass spectrum ranging from 0.05 to 0.8 of the solar mass. What is the nature…

Astrophysics · Physics 2007-05-23 A. V. Gurevich , K. P. Zybin , V. A. Sirota

Context. Strong lenses are a biased subset of the general population of galaxies. Aims. The goal of this work is to quantify how lens galaxies and lensed sources differ from their parent distribution, namely the strong lensing bias.…

Astrophysics of Galaxies · Physics 2023-09-29 Alessandro Sonnenfeld , Shun-Sheng Li , Giulia Despali , Raphael Gavazzi , Anowar J. Shajib , Edward N. Taylor

When gravitational waves pass through the nuclear star clusters of galactic lenses, they may be microlensed by the stars. Such microlensing can cause potentially observable beating patterns on the waveform due to waveform superposition and…

High Energy Astrophysical Phenomena · Physics 2021-03-10 Mark H. Y. Cheung , Joseph Gais , Otto A. Hannuksela , Tjonnie G. F. Li

Gravitational microlensing has proven to be a powerful tool in the study of quasars, providing some of the strongest limits on the scales of structure in the central engine. Typically sources are considered to be smoothly varying on some…

Astrophysics · Physics 2009-11-10 Geraint F. Lewis

We examine the effect that the shape of the source brightness profile has on the magnitude fluctuations of images in quasar lens systems due to microlensing. We do this by convolving a variety of accretion disk models (including Gaussian…

Astrophysics · Physics 2009-11-10 Michael J. Mortonson , Paul L. Schechter , Joachim Wambsganss

Here, we study the microlensing of radially pulsating stars. Discerning and characterizing the properties of distant, faint pulsating stars is achievable through high-cadence microlensing observations. Combining stellar variability period…

Solar and Stellar Astrophysics · Physics 2020-04-22 Sedighe Sajadian , Richard Ignace