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相关论文: Difference Image Analysis of Galactic Microlensing…

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We show how to significantly improve difference image analysis (DIA) of gravitationally lensed quasars over long periods of time using Gaia proper motions. DIA requires the subtraction of a reference image from the individual images of a…

星系天体物理 · 物理学 2024-01-19 C. Sorgenfrei , R. W. Schmidt , J. Wambsganss

Difference image analysis (DIA) is a powerful tool for studying time-variable phenomena, and has been used by many time-domain surveys. Most DIA algorithms involve matching the spatially-varying PSF shape between science and template…

Microlensing not only brings extra magnification lightcurves on top of the intrinsic ones but also shifts them in time domain, making the actual time-delays between images of strongly lensed active galactic nucleus change on the $\sim$…

宇宙学与河外天体物理 · 物理学 2021-01-06 Kai Liao

We describe a project of brown dwarf detection in the dark halo of a galaxy using the microlensing effect. We argue that monitoring pixels instead of stars could provide an enhancement in the number of detectable events. We estimate the…

天体物理学 · 物理学 2009-09-25 Alain Bouquet , Jean Kaplan , Anne-Laure Melchior , Yannick Giraud-Héraud , Paul Baillon

Gravitational microlensing, when finite size source effects are relevant, provides an unique tool for the study of source star stellar atmospheres through an enhancement of a characteristic polarization signal. This is due to the…

星系天体物理 · 物理学 2015-06-11 G. Ingrosso , S. Calchi Novati , F. De Paolis , Ph. Jetzer , A. A. Nucita , F. Strafella , A. F. Zakharov

Context: Understanding the source of systematic errors in photometry is essential for their calibration. Aims: We investigate how photometry performed on difference images can be influenced by errors in the photometric scale factor.…

天体物理仪器与方法 · 物理学 2015-05-27 D. M. Bramich , E. Bachelet , K. A. Alsubai , D. Mislis , N. Parley

We investigate whether Gaia can specify the binary fractions of massive stellar populations in the Galactic disk through astrometric microlensing. Furthermore, we study if some information about their mass distributions can be inferred via…

太阳与恒星天体物理 · 物理学 2015-04-14 Sedighe Sajadian

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…

地球与行星天体物理 · 物理学 2015-05-13 M. Hundertmark , F. V. Hessman , S. Dreizler

Microlensing has a unique advantage for detecting dark objects in the Milky Way, such as free-floating planets, neutron stars, and stellar-mass black holes. Most microlensing surveys focus on the Galactic bulge, where higher stellar density…

The gravitational fields of astrophysical bodies bend the light around them, creating multiple paths along which light from a distant source can arrive at Earth. Measuring the difference in photon arrival time along these different paths…

One possibility for detecting low-amplitude pulsational variations is through gravitational microlensing. During a microlensing event, the temporary brightness increase leads to improvement in the signal-to-noise ratio, and thereby better…

太阳与恒星天体物理 · 物理学 2021-09-01 Sedighe Sajadian , Richard Ignace , Hilding Neilson

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…

天体物理学 · 物理学 2007-05-23 A. F. Zakharov

Recently Alard\markcite{alard1996} proposed to detect the shift of a star's image centroid, $\delta x$, as a method to identify the lensed source among blended stars. Goldberg & Wo\'zniak\markcite{goldberg1997} actually applied this method…

天体物理学 · 物理学 2009-10-30 Cheongho Han , Youngjin Jeong

Microlensing light curves are now being monitored with the precision required to detect small perturbations due to planetary companions of the primary lens. Microlensing is complementary to other planetary search techniques in its potential…

天体物理学 · 物理学 2009-10-31 B. Scott Gaudi , Penny D. Sackett

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…

天体物理学 · 物理学 2009-10-22 Marc Kamionkowski

The microlensing parallax campaign with the $Spitzer$ space telescope aims to measure masses and distances of microlensing events seen towards the Galactic bulge, with a focus on planetary microlensing events. The hope is to measure how the…

地球与行星天体物理 · 物理学 2020-09-30 Naoki Koshimoto , David P. Bennett

The number and properties of observed gravitational microlensing events depend on the distribution and kinematics of stars and other compact objects along the line of sight. In particular, precise measurements of the microlensing optical…

For the first time we detected microlensing events at zero latitude in the Galactic bulge using the VISTA Variables in the Via Lactea Survey (VVV) data. We have discovered a total sample of N = 630 events within an area covering 20.7 sq.…

A comprehensive new approach is presented for deriving probability densities of physical properties characterizing lens or source that constitute an observed galactic microlensing event. While previously encountered problems are overcome,…

天体物理学 · 物理学 2009-11-11 M. Dominik

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…

天体物理仪器与方法 · 物理学 2016-03-21 Sohrab Rahvar