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Related papers: Gravitational Microlensing in NUT Space

200 papers

Numerical simulations and theoretical studies of the gravitational microlensing effect of a population of small bodies distributed along the line of sight to a compact light source such as a quasar indicate that caustic crossing effects…

Astrophysics · Physics 2007-05-23 M. R. S. Hawkins

The MACHO project is searching for dark matter in the form of massive compact halo objects (Machos), by monitoring the brightness of millions of stars in the Magellanic Clouds to search for gravitational microlensing events. Analysis of our…

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

The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been…

General Relativity and Quantum Cosmology · Physics 2016-12-07 G. Chapline , P. H. Frampton

If cluster dark matter is in the form of compact objects it will introduce fluctuations into the light curves of distant sources. Current searches for MACHOs in clusters of galaxies focus on monitoring quasars behind nearby systems. This…

Astrophysics · Physics 2009-10-31 Geraint F. Lewis , Rodrigo A. Ibata , J. Stuart B. Wyithe

One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves in spiral galaxies. In the framework of a baryonic scenario…

Astrophysics · Physics 2007-05-23 Philippe Jetzer

The observations of microlensing events in the Large Magellanic Cloud suggest that a sizable fraction ($\sim$ 50%) of the galactic halo is in the form of MACHOs (Massive Astrophysical Compact Halo Objects) with an average mass $\sim 0.27…

Astrophysics · Physics 2007-05-23 F. De Paolis , Ph. Jetzer , G. Ingrosso , M. Roncadelli

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 study the gravitational lensing properties of a massive object in a dark matter halo, concentrating on the critical curves and caustics of the combined lens. We model the system in the simplest approximation by a point mass embedded in a…

Astrophysics of Galaxies · Physics 2021-11-25 Michal Karamazov , Lukas Timko , David Heyrovsky

The distribution of masses of neutron stars, particularly the maximum mass value, is considered a probe of their formation, evolution and internal physics (i.e., equation of state). This mass distribution could in principle be inferred from…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Sofia Canevarolo , Loek van Vonderen , Nora Elisa Chisari

Using the fact that the null geodesics in NUT space lie on spatial cones, we consider the gravomagnetic lens effect on light rays passing a NUT deflector. We show that this effect changes the observed shape, size and orientation of a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mohammad Nouri-Zonoz , Donald Lynden-Bell

If the Galaxy contains ~10^{11}M_sol in cold gas clouds of ~Jovian mass and \~AU size, these clouds will act as converging lenses for optical light, magnifying background stars at a detectable rate. The resulting light curves can resemble…

Astrophysics · Physics 2009-10-30 B. T. Draine

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2007-05-23 Philippe Jetzer

Gravitational lensing describes the bending of the trajectories of light and gravitational waves due to the gravitational potential of a massive object. Strong lensing by galaxies can create multiple images with different overall…

General Relativity and Quantum Cosmology · Physics 2024-02-26 Simon M. C. Yeung , Mark H. Y. Cheung , Joseph A. J. Gais , Otto A. Hannuksela , Tjonnie G. F. Li

The status of the microlensing search for galactic dark matter in the form of massive astronomical compact halo objects (machos) is reviewed. Unresolved issues are discussed, as well as possible ways to solve these.

Astrophysics · Physics 2021-04-28 A. Milsztajn

It has been proposed that the Galaxy might contain a population of cold clouds in numbers sufficient to account for a substantial fraction of the total mass of the Galaxy. These clouds would have masses of the order of 10^{-3} Solar mass…

Astrophysics · Physics 2009-10-31 Roman R. Rafikov , Bruce T. Draine

In the context of this paper, microlenses present as oblate clusters of dark matter structures called massive astrophysical compact halo object(MACHO) in the galactic halo are considered. The NFW density profile [1] is derived from the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Tabib Rayed Hossain , Prabir Kumar Haldar , Mehedi Kalam

We study gravitational lensing of the cosmic neutrino background. This signal is undetectable for the foreseeable future, but there is a rich trove of information available. At least some of the neutrinos from the early universe will be…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-12 Joshua Yao-Yu Lin , Gilbert Holder

The main aim of microlensing experiments is to evaluate the mean mass of massive compact halo objects (MACHOs) and the mass fraction of the Galactic halo made by this type of dark matter. Statistical analysis shows that by considering a…

Astrophysics · Physics 2009-11-10 Sohrab Rahvar

We discuss the gravitational lensing of gravitational wave signals from coalescing binaries. We delineate the regime where wave effects are significant from the regime where geometric limit can be used. Further, we focus on the effect of…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-18 Ashish Kumar Meena , J S Bagla