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Related papers: Magnification bias as a novel probe for primordial…

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Was the primordial universe magnetized? The answer to this question would help explain the origin of micro-Gauss strength magnetic fields observed in galaxies. It is also of fundamental importance in developing a complete theory of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-14 Levon Pogosian , Alex Zucca

We reconstruct the 3D structure of magnetic fields, which were seeded by density perturbations during the radiation dominated epoch of the Universe and later on were evolved by structure formation. To achieve this goal, we rely on three…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-21 Sebastian Hutschenreuter , Sebastian Dorn , Jens Jasche , Franco Vazza , Daniela Paoletti , Guilhem Lavaux , Torsten A. Enßlin

The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It has…

The existence of magnetic fields in the universe is unmistakable. They are observed at all scales from stars to galaxy clusters. However, the origin of these fields remains enigmatic. It is believed that magnetic field seeds may have…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Orfeu Bertolami , Maria Margarida Lima , Filipe C. Mena

We propose that some of the high-latitude unidentified EGRET gamma-ray sources could be the result of gravitational lensing amplification of the innermost regions of distant, faint, active galactic nuclei. These objects have gamma-ray…

Astrophysics · Physics 2009-11-07 Diego F. Torres , Gustavo E. Romero , Ernesto F. Eiroa

We propose a new approach for measuring the mass profile and shape of groups and clusters of galaxies, which uses lensing magnification of distant background galaxies. The main advantage of lensing magnification is that, unlike lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Ludovic Van Waerbeke , Hendrik Hildebrandt , Jes Ford , Martha Milkeraitis

Only certain galaxies are included in surveys: those bright and large enough to be detectable as extended sources. Because gravitational lensing can make galaxies appear both brighter and larger, the presence of foreground inhomogeneities…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Fabian Schmidt , Eduardo Rozo , Scott Dodelson , Lam Hui , Erin Sheldon

Magnetic fields appear to be ubiquitous in astrophysical environments. Their existence in the intracluster medium is established through observations of synchrotron emission and Faraday rotation. On the other hand, the nature of magnetic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Dongsu Ryu , Dominik R. G. Schleicher , Rudolf A. Treumann , Christos G. Tsagas , Lawrence M. Widrow

Primordial magnetic fields generated in the very early universe are one of the candidates for the origin of magnetic fields observed in galaxy clusters. After recombination, the Lorentz force acts on the residual ions and electrons to…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Hiroyuki Tashiro , Naoshi Sugiyama

We investigate the constraints on primordial non-Gaussianity with varied bispectrum shapes that can be derived from the power spectrum of galaxies and clusters of galaxies detected in future wide field optical/near-infrared surveys. Having…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Cosimo Fedeli , Carmelita Carbone , Lauro Moscardini , Andrea Cimatti

Magnification bias offers a uniquely powerful and independent route to cosmological information. As a gravitational-lensing observable, it probes galaxy-matter correlations without relying on galaxy shapes, PSF modelling, or…

The origin of large-scale magnetic fields, detected in some low-mass (dwarf and irregular) galaxies via polarised synchrotron emission and Faraday rotation, remained unexplained for a long time. We suggest that mean-field dynamo can be…

Astrophysics of Galaxies · Physics 2019-10-16 Prasanta Bera , Anvar Shukurov , Kandaswamy Subramanian

We study the effect of magnification in the Dark Energy Survey Year 3 analysis of galaxy clustering and galaxy-galaxy lensing, using two different lens samples: a sample of Luminous red galaxies, redMaGiC, and a sample with a…

Large scale strong magnetic fields in galaxies are generally thought to have been generated by a mean field dynamo. In order to have generated the fields observed, the dynamo would have had to have operated for a sufficiently long period of…

Astrophysics · Physics 2007-05-23 A. Kandus , R. Opher , S. R. M. Barros

We apply a new method to measure primordial non-Gaussianity, using the cross-correlation between galaxy surveys and the CMB lensing signal to measure galaxy bias on very large scales, where local-type primordial non-Gaussianity predicts a…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-06 Tommaso Giannantonio , Will J. Percival

Magnetic fields play a pivotal role in the physics of interstellar medium in galaxies, but there are few observational constraints on how they evolve across cosmic time. Spatially resolved synchrotron polarization maps at radio wavelengths…

Astrophysics of Galaxies · Physics 2017-08-30 S. A. Mao , C. Carilli , B. M. Gaensler , O. Wucknitz , C. Keeton , A. Basu , R. Beck , P. P. Kronberg , E. Zweibel

There is strong observational evidence for the presence of large-scale magnetic fields MF in galaxies and clusters, with strength $\sim \mu$G and coherence lenght on the order of Kpc. However its origin remains as an outstanding problem.…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-08 Eduard F. Piratova , Edilson A. Reyes , Héctor J. Hortúa

Applying the known physics of plasmas to the evolution of galaxies and quasars in the Early Universe, a unique "Strong" Magnetic Field Modsl (SMF) was created that explains the origin of a very large-scale primordial magnetic field in each…

Astrophysics · Physics 2007-05-23 Howard D. Greyber

We discuss how small-scale density perturbations on the Fresnel scale affect amplitudes and phases of gravitational waves that are magnified by gravitational lensing in geometric optics. We derive equations that connect the small-scale…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Masamune Oguri , Ryuichi Takahashi

When gravitational waves pass through the nuclear star clusters of galactic lenses, they may be microlensed by the stars. Such microlensing can cause potentially observable beating patterns on the waveform due to waveform superposition and…

High Energy Astrophysical Phenomena · Physics 2021-03-10 Mark H. Y. Cheung , Joseph Gais , Otto A. Hannuksela , Tjonnie G. F. Li
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