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相关论文: Ultra-high angular resolution by gravitational mic…

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We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…

天体物理学 · 物理学 2009-11-07 Eric Agol

If the dark halo matter is primarily composed of MACHOs toward the lower end of the possible detection range ($ < 10^{-3}$ $M_{\odot}$) a fraction of the lens detection events should involve the lens crossing directly in front of the disk…

天体物理学 · 物理学 2009-10-22 Robert J. Nemiroff , W. A. D. Thulsi Wickramasinghe

Inverse Problem techniques offer powerful tools which deal naturally with marginal data and asymmetric or strongly smoothing kernels, in cases where parameter-fitting methods may be used only with some caution. Although they are typically…

天体物理学 · 物理学 2007-05-23 Norman Gray , Iain J. Coleman

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…

天体物理学 · 物理学 2009-11-13 E. Zackrisson , T. Riehm

We present a direct detection of the gravitational lens that caused the microlensing event MACHO-95-BLG-37. This is the first fully resolved microlensing system involving a source in the Galactic bulge, and the second such system in…

天体物理学 · 物理学 2009-11-13 S. Kozlowski , P. R. Wozniak , S. Mao , A. Wood

The MACHO project carries out regular photometric monitoring of millions of stars in the Magellanic Clouds and Galactic Bulge, to search for very rare gravitational microlensing events due to compact objects in the galactic halo and disk. A…

We study a sample of 16 microlensed Galactic bulge main sequence turnoff region stars for which high dispersion spectra have been obtained with detailed abundance analyses. We demonstrate that there is a very strong and highly statistically…

Gravitational microlensing occurs when a foreground star happens to pass very close to our line of sight to a more distant background star. The foreground star acts as a lens, splitting the light from the source star into two images, which…

地球与行星天体物理 · 物理学 2010-02-03 B. Scott Gaudi

Modern surveys of gravitational microlensing events have progressed to detecting thousands per year. Surveys are capable of probing Galactic structure, stellar evolution, lens populations, black hole physics, and the nature of dark matter.…

We present results of recurrence analysis of 46 active galactic nuclei (AGN) using light curves from the 157-month catalog of the Swift Burst Alert Telescope (BAT) in the 14-150 keV band. We generate recurrence plots and compute recurrence…

高能天体物理现象 · 物理学 2022-11-28 R. A. Phillipson , M. S. Vogeley , P. T. Boyd

We analyze the first-year MACHO collaboration observations of microlensing towards the Galactic center using a new direct likelihood technique that is sensitive to the distribution of the events on the sky. We consider the full set of 41…

天体物理学 · 物理学 2007-05-23 Geza Gyuk

The existence of a massive black hole in the center of the Milky Way, coinciding with the radio source Sgr A*, is being established on more and more solid ground. In principle, this black hole, acting as a gravitational lens, is able to…

天体物理学 · 物理学 2011-02-11 Valerio Bozza , Luigi Mancini

In this paper we show that to explain the observed distribution of amplitudes in a large sample of quasar lightcurves, a significant contribution from microlensing is required. This implies the existence of a cosmologically distributed…

宇宙学与河外天体物理 · 物理学 2022-04-21 M. R. S. Hawkins

Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in…

宇宙学与河外天体物理 · 物理学 2024-05-29 Yarone M. Tokayer , Isaque Dutra , Priyamvada Natarajan , Guillaume Mahler , Mathilde Jauzac , Massimo Meneghetti

In order to examine the relative importance of powerful starbursts and Compton-thick AGNs in NGC 6240, we have obtained mid-infrared images and low-resolution spectra of the galaxy with sub-arcsecond spatial resolution using the Keck…

天体物理学 · 物理学 2008-11-26 E. Egami , G. Neugebauer , B. T. Soifer , K. Matthews , E. E. Becklin , M. E. Ressler

I show that the standard microlensing technique to measure the angular radius of a star using color/surface-brightness relations can be inverted, via late-time proper motion measurements, to calibrate these relations. The method is…

太阳与恒星天体物理 · 物理学 2015-06-22 Andrew Gould

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…

天体物理学 · 物理学 2009-11-10 Geraint F. Lewis

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 2017-08-23 Alexander F. Zakharov

Astrophysical implications of gravitational microlensing of gravitational waves emitted by rotating neutron stars (NSs) are investigated. In particular, attention is focused on the following situations: i) NSs in the galactic bulge lensed…

天体物理学 · 物理学 2009-10-31 F. De Paolis , G. Ingrosso , A. A. Nucita