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Microlensing searches aim to detect compact halo dark matter via its gravitational lensing effect on stars within the Large Magellanic Cloud. The most recent results have led to the claim that roughly one fifth of the galactic halo dark…

Astrophysics · Physics 2009-11-07 Anne M Green , Karsten Jedamzik

We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (or Machos), using gravitational microlensing of background stars. This search uses a very large format CCD camera on the…

Current theories of structure formation predict specific density profiles of galaxy dark matter haloes, and with weak gravitational lensing we can probe these profiles on several scales. On small scales, higher-order shape distortions known…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Malin Velander , Konrad Kuijken , Tim Schrabback

We examined the reliability of estimates of pseudoisothermal, Burkert and NFW dark halo parameters for the methods based on the mass-modelling of the rotation curves.To do it we constructed the $\chi^2$ maps for the grid of the dark matter…

Astrophysics of Galaxies · Physics 2016-08-24 Anna Saburova , Anastasia Kasparova , Ivan Katkov

A new method for measuring gravitational lensing with high redshift type Ia supernovae is investigated. The method utilizes correlations between foreground galaxies and supernova brightnesses to substantially reduce possible systematic…

Astrophysics · Physics 2017-03-22 R. Benton Metcalf

We investigate 3D density and weak lensing profiles of dark matter haloes predicted by a cosmology-rescaling algorithm for $N$-body simulations. We extend the rescaling method of Angulo & White (2010) and Angulo & Hilbert (2015) to improve…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Malin Renneby , Stefan Hilbert , Raúl E. Angulo

Weak gravitational lensing is now established as a powerful method to measure mass fluctuations in the universe. It relies on the measurement of small coherent distortions of the images of background galaxies. Even low-level correlations in…

Astrophysics · Physics 2009-07-09 Alan Heavens , Alexandre Refregier , Catherine Heymans

The goal of this paper is to develop a machine learning model to analyze the main gravitational lens and detect dark substructure (subhalos) within simulated images of strongly lensed galaxies. Using the technique of image segmentation, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-27 Bryan Ostdiek , Ana Diaz Rivero , Cora Dvorkin

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…

We investigate the weak lensing shear due to dark matter galaxy halos whose mass distributions, as projected on the sky, are nearly elliptical. The shear pattern due to these halos is anisotropic about the lens centers and we quantify the…

Astrophysics · Physics 2007-05-23 T. G. Brainerd , C. O. Wright

Gravitational waves (GWs) can be deflected, similarly to electromagnetic (EM) waves, by massive objects through the phenomenon of gravitational lensing. The importance of gravitational lensing for GW astronomy is becoming increasingly…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Eungwang Seo , Tjonnie Guan Feng Li , Martin Anthony Hendry

High-resolution N-body simulations of dark matter halos indicate that the Milky Way contains numerous subhalos. When a dark matter subhalo passes in front of a star, the light from that star will be deflected by gravitational lensing,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Adrienne L. Erickcek , Nicholas M. Law

We use weak gravitational lensing to measure mean mass profiles around Locally Brightest Galaxies (LBGs). These are selected from the SDSS/DR7 spectroscopic and photometric catalogues to be brighter than any neighbour projected within 1.0…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-15 Wenting Wang , Simon White , Rachel Mandelbaum , Bruno Henriques , Michael E. Anderson , Jiaxin Han

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…

We investigate the feasibility of reconstructing the radial intensity profile of extended stellar sources by inverting their microlensed light curves. Using a simple, linear, limb darkening law as an illustration, we show that the intensity…

Astrophysics · Physics 2009-10-30 M. A. Hendry , I. J. Coleman , N. Gray , A. M. Newsam , J. F. L. Simmons

Observations of microlensing transit events can be used to measure the limb darkening of the lensed star. We discuss the advantages and drawbacks of several microlensing light curve inversion methods. The method of choice in this work is…

Astrophysics · Physics 2009-11-07 David Heyrovsky

The gravitational lensing of supermassive black holes surrounded by dark matter halo has attracted a great number of interests in recent years. However, many studies employed simplified dark matter density models, which makes it very hard…

General Relativity and Quantum Cosmology · Physics 2024-10-25 Yi-Gao Liu , Chen-Kai Qiao , Jun Tao

Since the strength of weak gravitational lensing is proportional to the mass along the line of sight, it might be possible to use lensing data to find the masses of individual dark matter clusters. Unfortunately, the effect on the lensing…

Astrophysics · Physics 2009-08-18 Roland de Putter , Martin White

In this work we study the inverse problem related to the emission of Hawking radiation. We first show how the knowledge of greybody factors of different angular contributions $l$ can be used to constrain the width of the corresponding black…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Sebastian H. Völkel , Roman Konoplya , Kostas D. Kokkotas

Empirical methods for connecting galaxies to their dark matter halos have become essential for interpreting measurements of the spatial statistics of galaxies. In this work, we present a novel approach for parameterizing the degree of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-30 Benjamin V. Lehmann , Yao-Yuan Mao , Matthew R. Becker , Samuel W. Skillman , Risa H. Wechsler
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