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We consider a contribution of microlensing in 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 distances…

Astrophysics · Physics 2009-11-10 A. F. Zakharov , L. C. Popovic , P. Jovanovic

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

We consider the contribution of microlensing to the AGN Fe K$\alpha$ line and X-ray continuum amplification and variation. To investigate the variability of the line and X-ray continuum, we studied the effects of microlensing on quasar…

Astrophysics · Physics 2007-05-23 L. C. Popovic , P. Jovanovic , T. Petrovic , V. N. Shalyapin

Variability in gravitationally lensed quasars can be due to intrinsic fluctuations of the quasar or due to ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced variability can be…

Astrophysics · Physics 2007-05-23 Joachim Wambsganss

The spatial distribution of compact dark matter in our Galaxy can be determined in a few years of monitoring Galactic globular clusters for microlensing. Globular clusters are the only dense fields of stars distributed throughout the…

Astrophysics · Physics 2009-10-30 James E. Rhoads , Sangeeta Malhotra

There are two possible causes of variability in gravitationally lensed quasars: intrinsic fluctuations of the quasar and ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced…

Astrophysics · Physics 2009-10-31 Joachim Wambsganss

A substantial part of the dark matter of the Universe could be in the form of compact objects (MACHOs), detectable through gravitational microlensing effects as they pass through the line of sight to background light sources. So far, most…

Astrophysics · Physics 2009-11-13 E. Zackrisson , T. Riehm

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

A recently discovered inverse correlation between QSO redshift and long-term continuum variability timescales was suggested to be the signature of microlensing on cosmological scales (Hawkins 1993). A general theoretical method for…

Astrophysics · Physics 2015-06-24 Tal Alexander

It is conventional to calculate the probability of microlensing for a cosmologically distant source based on the Press-Gunn approximation that the lensing objects are uniformly and randomly distributed in the intervening space with a…

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

We consider the influence of (milli/micro)lensing on the spectra of lensed QSOs. We propose a method for the observational detection of microlensing in the spectra of lensed QSOs and apply it to the spectra of the three lensed QSOs (PG…

Astrophysics · Physics 2009-11-10 L. C. Popovic , G. Chartas

We examine whether a cosmologically significant distribution of dark galaxy group or cluster-sized objects can have an optical depth for multiple imaging of distant background sources which is comparable to that from known galaxies while at…

Astrophysics · Physics 2011-02-11 Yu-Chung N. Cheng , Lawrence M. Krauss

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

In this article we review the astrophysical application of gravitational microlensing. After introducing the history of gravitational lensing, we present the key equations and concept of microlensing. The most frequent microlensing events…

Instrumentation and Methods for Astrophysics · Physics 2016-03-21 Sohrab Rahvar

Disk-halo models of the Galaxy and LMC are constructed and used to analyse the microlensing data-set. Deflectors in the LMC bar, disk and halo provide an optical depth to microlensing of $\sim 2 \times 10^{-7}$. Deflectors in the Galactic…

Astrophysics · Physics 2016-06-08 N. W. Evans

We discuss the effects of microlensing on the broad emission lines (BELs) of QSOs in the light of recent determinations of the size of the broad line region (BLR) and its scaling with QSO luminosity. Microlensing by star-sized objects can…

Astrophysics · Physics 2009-11-07 C. Abajas , E. Mediavilla , J. A. Munoz , L. C. Popovic , A. Oscoz

According to the cold dark matter scenario, a large number of dark subhalos should be located within the halo of each Milky-way sized galaxy. One promising possibility for detecting such subhalos is to try to observe their gravitational…

Astrophysics · Physics 2008-02-11 Kaj Wiik , Erik Zackrisson , Teresa Riehm

The most important uncertainty in the results of gravitational microlensing experiments comes from the difficulties of photometry caused by blending of source stars. Recently Nemiroff (1997) pointed out that the results of microlensing…

Astrophysics · Physics 2007-05-23 Seunghun Lee , Cheongho Han

Gravitational lensing can be used to analyze the redshift distribution of faint galaxies. In particular the magnification bias modifies locally the galaxy number density of lensed sources observed in lensing clusters. This depletion area…

Astrophysics · Physics 2007-05-23 Y. Mellier

We explore the possibility of attributing the recent discovery of the hard X-ray variable source CXOM82 J095550.2+694047 in M82 to the gravitational magnification by an intervening stellar obeject along the line of sight as microlens. The…

Astrophysics · Physics 2007-05-23 Da-Ming Chen
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