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Related papers: Polarization in microlensing towards the Galactic …

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We study the incidence of the underlying host galaxy light on the measured optical linear polarization of blazars. Our methodology consists of the implementation of simulated observations obtained under different atmospheric conditions,…

Astrophysics · Physics 2009-11-13 I. Andruchow , Sergio A. Cellone , Gustavo E. Romero

Simulations of planetary microlensing at high magnification that were carried out on a cluster computer are presented. It was found that the perturbations due to two-thirds of all planets occur in the time interval [-0.5t_FWHM, 0.5t_ FWHM]…

Astrophysics · Physics 2009-11-07 N. J. Rattenbury , I. A. Bond , J. Skuljan , P. C. M. Yock

The gravitational microlensing technique allows the discovery of exoplanets around stars distributed in the disk of the galaxy towards the bulge. However, the alignment of two stars that led to the discovery is unique over the timescale of…

Earth and Planetary Astrophysics · Physics 2015-12-09 I. Boisse , A. Santerne , J. -P. Beaulieu , W. Fakhardji , N. C. Santos , P. Figueira , S. G. Sousa , C. Ranc

POLAR is a novel compact Compton X-ray polarimeter designed to measure the linear polarization of the prompt emission of Gamma Ray Bursts (GRB) and other strong transient sources such as soft gamma repeaters and solar flares in the energy…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Silvio Orsi

Among various techniques to search for extra-solar planets, microlensing has some unique characteristics. Contrary to all other methods which favour nearby objects, microlensing is sensitive to planets around stars at distances of several…

In order to understand the nature of the lenses that generate microlensing events, one would like to measure their mass, distance, and velocity. Unfortunately, current microlensing experiments measure only one parameter of the events, the…

Astrophysics · Physics 2009-10-28 B. Scott Gaudi , Andrew Gould

We report observations of the linear polarization of a sample of 49 nearby bright stars measured to sensitivities of between ~1 and 4 x 10^-6. The majority of stars in the sample show measurable polarization, but most polarizations are…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jeremy Bailey , P. W. Lucas , J. H. Hough

We present a statistical analysis of Galactic interstellar polarization from the largest compilation available of starlight data. The data comprises ~ 9300 stars of which we have selected ~ 5500 for our analysis. We find a nearly linear…

Astrophysics · Physics 2009-11-06 Pablo Fosalba , Alex Lazarian , Simon Prunet , Jan A. Tauber

This is a preliminary report on the application of Difference Image Analysis (DIA) to galactic bulge images. The aim of this analysis is to increase the sensitivity to the detection of gravitational microlensing. We discuss how the DIA…

Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…

Astrophysics · Physics 2007-05-23 A. F. Zakharov

Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…

Astrophysics · Physics 2017-08-23 Alexander F. Zakharov

Context: Polarimetry is a very powerful tool to uncover various properties of astronomical objects that remain otherwise hidden in standard imaging or spectroscopic observations. However, the reliable measurement of the low polarization…

Instrumentation and Methods for Astrophysics · Physics 2020-02-12 S. González-Gaitán , A. M. Mourão , F. Patat , J. P. Anderson , A. Cikota , K. Wiersema , A. B. Higgins , K. Silva

Interstellar linear polarization occurs when starlight passes through elongated dust grains aligned by interstellar magnetic fields. The observed polarization can come from different dust structures along the line of sight (LOS). By…

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev

Emission from blazar jets in the ultraviolet, optical, and infrared is polarized. If these low-energy photons were inverse-Compton scattered, the upscattered high-energy photons retain a fraction of the polarization. Current and future…

High Energy Astrophysical Phenomena · Physics 2015-02-03 Nachiketa Chakraborty , Vasiliki Pavlidou , Brian Fields

Some bright cD galaxies in cluster cooling flows have Thomson optical depths exceeding 0.01. A few percent of their luminosity is scattered and appears as diffuse polarized emission. We calculate the scattering process for different…

Astrophysics · Physics 2009-10-22 B. W. Murphy , D. F. Chernoff

The measurement of the integrated optical polarization of weakly gravitationally lensed galaxies can provide considerable constraints on lens models. The method outlined depends on fact that the orientation of the direction of optical…

Astrophysics · Physics 2009-10-30 Edouard Audit , John F. L. Simmons

We discuss high-resolution, time-resolved spectra of the caustic exit of the binary microlensing event OGLE 2002-BUL-69 obtained with UVES on the VLT. The source star is a G5III giant in the Galactic Bulge. During such events, the source…

If stars at the lower end of the main sequence are responsible for the microlensing events observed in the Galactic bulge, then light from the lensing star contributes to the observed brightness. The background and lensing stars generally…

Astrophysics · Physics 2009-10-22 Marc Kamionkowski

The phenomenon of microlensing has successfully been used to detect extrasolar planets. By observing characteristic, rare deviations in the gravitational microlensing light curve one can discover that a lens is a star--planet system. In…

Earth and Planetary Astrophysics · Physics 2014-04-15 Krzysztof Rybicki , Łukasz Wyrzykowski
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