English
Related papers

Related papers: Microlensing evidence for super-Eddington disk acc…

200 papers

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 lensing of a quasar by a spiral galaxy should often be accompanied by damped Lyman-alpha absorption and dust extinction due to the intervening gaseous disk. In nearly edge-on configurations, the surface mass density of the gas…

Astrophysics · Physics 2009-10-30 Matthias Bartelmann , Abraham Loeb

Multiply-imaged quasars and AGNs observed in the mid-infrared (MIR) range are commonly assumed to be unaffected by the microlensing produced by the stars in their lensing galaxy. In this paper, we investigate the validity domain of this…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-07 D. Sluse , M. Kishimoto , T. Anguita , O. Wucknitz , J. Wambsganss

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

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

Microlensing perturbations to the flux ratios of gravitationally lensed quasar images can vary with wavelength because of the chromatic dependence of the accretion disk's apparent size. Multiwavelength observations of microlensed quasars…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-25 Jeffrey A. Blackburne , David Pooley , Saul Rappaport , Paul L. Schechter

Gravitational microlensing of quasars by stars in external galaxies can introduce fluctuations in the centroid of the ``point-like'' macro--images. The induced shifts are extremely small, on micro--arcsecond scales, below the limits of…

Astrophysics · Physics 2009-10-30 Geraint F. Lewis , Rodrigo A. Ibata

Quasar microlensing offers a unique opportunity to resolve tiny sources in distant active galactic nuclei and study compact object populations in lensing galaxies. We therefore searched for microlensing-induced variability of the…

We study the influence of gravitational microlensing on the AGN Fe K-alpha line confirming that unexpected enhancements recently detected in the iron line of some AGNs can be produced by this effect. We use a ray tracing method to study the…

Astrophysics · Physics 2009-11-07 L. C. Popovic , E. G. Mediavilla , P. Jovanovic , J. A. Munoz

Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Georgios Vernardos , Christopher J. Fluke

Since the radiation from different portions in the central region of a quasar can be successively amplified during a microlensing event, microlensing light curves provide us with fruitful information regarding the emissivity distribution of…

Astrophysics · Physics 2007-05-23 Shin Mineshige , Atsunori Yonehara

We investigate the chance of detecting proto-planetary or debris disks in stars that induce microlensing events (lenses). The modification of the light curves shapes due to occultation and extinction by the disks as well as the additional…

Earth and Planetary Astrophysics · Physics 2015-05-13 M. Hundertmark , F. V. Hessman , S. Dreizler

Gravitational lensing by a spiral galaxy occurs when the line-of-sight to a background quasar passes within a few kpc from the center of the galactic disk. Since galactic disks are rich in neutral hydrogen, the quasar spectrum will likely…

Astrophysics · Physics 2016-08-30 Abraham Loeb

Microlensings events are predicted for the light coming from cosmological sources. In addition to the microlensing due to gravitation lensing, microlensing produced also by refraction of light due to either ionized, or not, gas clouds can…

Instrumentation and Methods for Astrophysics · Physics 2016-10-19 G. Cavalleri , F. Barbero , E. Tonni , S. Covino

Rapid, large amplitude variability at optical to X-ray wavelengths is now seen in an increasing number of Seyfert galaxies and luminous quasars. The variations imply a global change in accretion power, but are too rapid to be communicated…

Astrophysics of Galaxies · Physics 2018-11-28 Jason Dexter , Mitchell C. Begelman

We present the results of the first long-term (2.2 years) spectroscopic monitoring of a gravitationally lensed quasar, namely the Einstein Cross Q2237+0305. The goal of this paper is to present the observational facts to be compared in…

Astrophysics · Physics 2009-11-13 A. Eigenbrod , F. Courbin , D. Sluse , G. Meylan , E. Agol

We investigate gravitational lensing by a realistic model of disk galaxies. Most of the mass is contained in a large spherical isothermal dark matter halo, but the potential is modified significantly in the core by a…

Astrophysics · Physics 2009-10-30 Ole Moeller , A. W. Blain

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

We compare the planet-to-star mass-ratio distribution measured by gravitational microlensing to core accretion theory predictions from population synthesis models. The core accretion theory's runaway gas accretion process predicts a dearth…

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