English
Related papers

Related papers: Extended Source Effects in Astrometric Gravitation…

200 papers

Gravitational waves propagate along null geodesics like light rays in the geometrical optics approximation, and they may have a chance to suffer from gravitational lensing by intervening objects, as is the case for electromagnetic waves.…

General Relativity and Quantum Cosmology · Physics 2010-10-12 Yousuke Itoh , Toshifumi Futamase , Makoto Hattori

We consider the effects induced by the presence of hot and cold spots on the source star in the light curves of simulated microlensing events due to either single or binary lenses taking into account the rotation of the source star and the…

Solar and Stellar Astrophysics · Physics 2017-03-23 Mosè Giordano , Achille A. Nucita , Francesco De Paolis , Gabriele Ingrosso

Using the astrometry of microlensing events we study the effect of angular momentum as compared to that of the parallax. For a rotating lens it is shown that the effect of the angular momentum deviates the center of images from that in the…

Astrophysics · Physics 2007-05-23 Habib Ebrahimnejad Rahbari , Mohammad Nouri-Zonoz , Sohrab Rahvar

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the…

Astrophysics · Physics 2009-10-31 Neda Safizadeh , Neal Dalal , Kim Griest

We investigate the effect of a single microlens on Stokes parameters. Semi-analytical formulae of the microlensed Stokes parameters are derived. The formulae not only reduce the double integrals in the estimations of those quantities but…

Astrophysics · Physics 2016-08-30 Hiroshi Yoshida

To determine the magnification of an extended source caused by gravitational lensing one has to perform a two-dimensional integral over point-source magnifications in general. Since the point-source magnification jumps to an infinite value…

Astrophysics · Physics 2011-05-23 M. Dominik

The density of stars and MACHOs in the universe could theoretically be determined or limited by simultaneous measurements of compact sources by well separated observers. A gravitational lens effect would be expected to create a slight…

Astrophysics · Physics 2009-10-30 Robert J. Nemiroff

Astrometric observations of microlensing events can be used to obtain important information about lenses. During these events, the shift of the position of the multiple image centroid with respect to the source star location can be…

Earth and Planetary Astrophysics · Physics 2018-07-18 Lindita Hamolli , Mimoza Hafizi , Francesco De Paolis , Achille A. Nucita

Due to the choice of very dense star fields for a higher event rate, the current microlensing searches suffer from large uncertainties caused by blending effect. To measure light variations of microlensing events free from the effect of…

Astrophysics · Physics 2007-05-23 Cheongho Han

Massive galactic lenses with large Einstein Radii should cause a measurable astrometric microlensing effect, i.e. the light centroid shift due to the motion of the two images. Such a shift in the position of a background star due to…

Solar and Stellar Astrophysics · Physics 2022-10-26 Maja Jabłońska , Łukasz Wyrzykowski , Krzysztof A. Rybicki , Katarzyna Kruszyńska , Zofia Kaczmarek , Zephyr Penoyre

To generate the standard microlensing light curve one assumes that the relative motion of the source, the lens, and the observer is linear. In reality, the relative motion is likely to be more complicated due to accelerations of the…

Astrophysics · Physics 2009-11-07 M. C. Smith , S. Mao , B. Paczynski

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

Astrophysics · Physics 2009-11-13 Martin C. Smith , Przemyslaw Wozniak , Shude Mao , Takahiro Sumi

When a microlensing light curve is contaminated by blended light from unresolved stars near the line of sight to the lensed star, the light curve shape and corresponding parameterization for the event will differ from the values expected…

Astrophysics · Physics 2009-10-31 Cheongho Han

We measure the astrometric shifts of the light centroids for the microlensing events in the OGLE-1 database. Of the 15 consistently detected events, 7 had significant shifts which we were able to measure with a fair degree of confidence.…

Astrophysics · Physics 2007-05-23 David M. Goldberg , Przemyslaw Wozniak

The effect of gravitational lensing on cosmic microwave background (CMB) anisotropies is investigated using the power spectrum approach. The lensing effect can be calculated in any cosmological model by specifying the evolution of…

Astrophysics · Physics 2009-10-28 Uros Seljak

The detection of anomalies in gravitational microlensing events is nowadays one of the main goals among the microlensing community. In the case of single-lens events, these anomalies can be caused by the finite source effects, that is when…

Earth and Planetary Astrophysics · Physics 2016-07-12 Lindita Hamolli , Mimoza Hafizi , Francesco De Paolis , Achille A. Nucita

In the current paper we consider the prospects of observation of gravitationally lensed sources in far-infrared and submillimeter wavelength ranges by the future space telescopes equipped with actively cooled main mirrors. We consider the…

Astrophysics of Galaxies · Physics 2020-04-29 T. I. Larchenkova , A. A. Ermash , A. G. Doroshkevich

Counter to intuition, the images of an extended galaxy lensed by a moving galaxy cluster should have slightly different spectra in any metric gravity theory. This is mainly for two reasons. One relies on the gravitational potential of a…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-03 Indranil Banik , Hongsheng Zhao

The extended source effect on microlensing magnification is non-negligible and must be taken into account for in an analysis of microlensing. However, the evaluation of the extended source magnification is numerically expensive because it…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 Sunao Sugiyama

We have developed a perturbative approach to microlensing due to an extrasolar planetary lens. In particular, we have found analytic formulae for triple images. We have used the formulae to investigate the astrometric microlensing due to…

Astrophysics · Physics 2009-11-07 Hideki Asada