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相关论文: Limiting Magnetic Fields in the Cosmic Web with Di…

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The structure of magnetic fields in galaxies remains poorly constrained, despite the importance of magnetism in the evolution of galaxies. Radio synchrotron and far-infrared (FIR) polarization and polarimetric observations are the best…

We present the newest statistical and numerical analysis of the matter and cosmic microwave background power spectrum with effects of the primordial magnetic field (PMF) included. New limits to the PMF strength and power spectral index are…

宇宙学与河外天体物理 · 物理学 2010-04-06 Dai G. Yamazaki , Kiyotomo Ichiki , Toshitaka Kajino , Grant. J. Mathews

We present the first observational limits on the predicted synchrotron signals from particle Dark Matter annihilation models in dwarf spheroidal galaxies at radio frequencies below 1 GHz. We use a combination of survey data from the…

高能天体物理现象 · 物理学 2019-08-14 Arpan Kar , Sourav Mitra , Biswarup Mukhopadhyaya , Tirthankar Roy Choudhury , Steven Tingay

Cosmic-ray scatterings on the cosmic neutrino background induce a flux of gamma-rays and X-rays from boosted meson decays and charged lepton processes. Here we present the first estimate of this flux and its cumulative cosmological…

高能物理 - 唯象学 · 物理学 2026-02-25 Gonzalo Herrera , Abraham Loeb

We compare a set of contemporary Galactic magnetic field (GMF) models with polarized synchrotron observations from the S-PASS and C-BASS radio surveys and combine them to create a reconstructed 4.76~GHz full sky map. Pixels that potentially…

We present our attempts to detect magnetic fields in filamentary large-scale structure (LSS) by observing polarized synchrotron emission emitted by structure formation shocks. Little is known about the strength and order of magnetic fields…

天体物理学 · 物理学 2009-11-13 Shea Brown , Lawrence Rudnick , Damon Farnsworth

Primordial magnetic fields (PMFs) play a pivotal role in influencing small-scale fluctuations within the primordial density field, thereby enhancing the matter power spectrum within the context of the $\Lambda$CDM model at small scales.…

宇宙学与河外天体物理 · 物理学 2024-09-02 Qile Zhang , Shang Li , Xiu-Hui Tan , Jun-Qing Xia

Primordial magnetic field (PMF) is one of the feasible candidates to explain observed large-scale magnetic fields, for example, intergalactic magnetic fields. We present a new mechanism that brings us information about PMFs on small scales…

宇宙学与河外天体物理 · 物理学 2020-05-28 Shohei Saga , Hiroyuki Tashiro , Shuichiro Yokoyama

We calculate the cosmic microwave background bispectrum of vector modes induced from primordial magnetic fields. We take into account the full angular dependence of the bispectrum and discuss the amplitude and also the shape of the…

宇宙学与河外天体物理 · 物理学 2011-02-25 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama , Kiyotomo Ichiki , Keitaro Takahashi

A new, much improved model of the Galactic Magnetic Field (GMF) is presented. We use the WMAP7 Galactic Synchrotron Emission map and more than forty thousand extragalactic rotation measures to constrain the parameters of the GMF model,…

星系天体物理 · 物理学 2015-06-04 Ronnie Jansson , Glennys R. Farrar

A primordial cosmological magnetic field induces and supports vorticity or Alfven waves, which in turn generate cosmic microwave background (CMB) anisotropies. A homogeneous primordial magnetic field with fixed direction induces…

天体物理学 · 物理学 2008-11-26 Gang Chen , Pia Mukherjee , Tina Kahniashvili , Bharat Ratra , Yun Wang

Mapping the intergalactic medium (IGM) in Lyman-$\alpha$ emission would yield unprecedented tomographic information on the large-scale distribution of baryons and potentially provide new constraints on the UV background and various feedback…

星系天体物理 · 物理学 2021-06-22 Joris Witstok , Ewald Puchwein , Girish Kulkarni , Renske Smit , Martin G. Haehnelt

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…

星系天体物理 · 物理学 2017-08-30 S. A. Mao , C. Carilli , B. M. Gaensler , O. Wucknitz , C. Keeton , A. Basu , R. Beck , P. P. Kronberg , E. Zweibel

We simulate propagation of cosmic ray nucleons above 10^{19} eV in scenarios where both the source distribution and magnetic fields within about 50 Mpc from us are obtained from an unconstrained large scale structure simulation. We find…

天体物理学 · 物理学 2009-11-07 Guenter Sigl , Francesco Miniati , Torsten Ensslin

Well-motivated models of dark matter often result in a population of electrons and positrons within galaxies produced through dark matter annihilation -- usually in association with gamma rays. As they diffuse through galactic magnetic…

高能物理 - 唯象学 · 物理学 2024-02-23 Mitchell J. Weikert , Matthew R. Buckley

The amplitude of the magnetic field surrounding the Galactic Centre (GC) on large scales (> 100 pc) has been uncertain by two orders of magnitude for several decades: different analyses report fields as weak as ~6 microG on the one hand and…

星系天体物理 · 物理学 2010-01-27 Roland M. Crocker

We analyse observational signatures of magnetic fields for simulations of a Milky-Way like disc with supernova-driven interstellar turbulence and self-consistent chemical processes. In particular, we post-process two simulations data sets…

星系天体物理 · 物理学 2022-03-29 Yoan Rappaz , Jennifer Schober , Philipp Girichidis

Cosmological simulations predict the presence of warm hot thermal gas in the cosmic filaments that connect galaxy clusters. This gas is thought to constitute an important part of the missing baryons in the Universe. In addition to the…

We have estimated the magnetic field strengths of a sample of seven galaxies using their non-thermal synchrotron radio emission at metre wavelengths, and assuming energy equipartition between magnetic fields and cosmic ray particles.…

星系天体物理 · 物理学 2023-02-22 Souvik Manna , Subhashis Roy

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and…

天体物理学 · 物理学 2009-11-13 Hiroyuki Tashiro , Naoshi Sugiyama , Robi Banerjee