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Related papers: A lower bound on the local extragalactic magnetic …

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If ultra-high-energy cosmic rays originate from extragalactic sources, the offsets of their arrival directions from these sources imply an upper limit on the strength of the extragalactic magnetic field. The Pierre Auger Collaboration has…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-11 J. D. Bray , A. M. M. Scaife

We take advantage of the wealth of rotation measures data contained in the NRAO VLA Sky Survey catalogue to derive new, statistically robust, upper limits on the strength of extragalactic magnetic fields. We simulate the extragalactic…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-18 Maxim S. Pshirkov , Peter G. Tinyakov , Federico R. Urban

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…

Astrophysics of Galaxies · Physics 2010-01-27 Roland M. Crocker

Recent work suggests that the cosmic ray spectrum may be dominated by Galactic sources up to ~10^{17.5} eV, and by an extra-Galactic component beyond, provided this latter cuts off below the transition energy. Here it is shown that this…

Astrophysics · Physics 2009-11-10 Martin Lemoine

New low-frequency 74 and 330 MHz observations of the Galactic center (GC) region reveal the presence of a large-scale ($6\arcdeg\times 2\arcdeg$) diffuse source of nonthermal synchrotron emission. A minimum energy analysis of this emission…

Astrophysics · Physics 2011-07-18 T. N. LaRosa , C. L. Brogan , S. N. Shore , T. J. Lazio , N. E. Kassim , M. E. Nord

Magnetic fields in galaxies are produced via the amplification of seed magnetic fields of unknown nature. The seed fields, which might exist in their initial form in the intergalactic medium, were never detected. We report a lower bound…

High Energy Astrophysical Phenomena · Physics 2014-11-21 Andrii Neronov , Ievgen Vovk

The extragalactic magnetic field could be detected by searching for signatures of the electromagnetic cascade initiated by high-energy photons on the intergalactic radiation and deflected by the field. This process produces a time delay and…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-04 Boris Stern , Igor Tkachev

Observations of AGNs and microquasars by ASCA, RXTE, Chandra and XMM-Newton indicate the existence of wide X-ray emission lines of heavy ionized elements in their spectra. The emission can arise in the inner parts of accretion discs where…

Astrophysics · Physics 2009-11-07 A. F. Zakharov , N. S. Kardashev , V. N. Lukash , S. V. Repin

The current state of research of the Galactic magnetic field is reviewed critically. The average (equipartition) strength of the total field derived from radio synchrotron data is 6 +/- 2 muG locally and about 10 +/- 3 muG at 3 kpc Galactic…

Astrophysics · Physics 2021-04-28 Rainer Beck

It is assumed that long range coherent magnetic fields in the universe were spontaneously generated at high temperature due to vacuum polarization of non-Abelian gauge fields, and resulted in the present intergalaxy magnetic field. The zero…

High Energy Physics - Phenomenology · Physics 2011-06-27 E. Elizalde , V. Skalozub

The strength and spectrum of the extragalactic magnetic field are still unknown. Its measurement would help answer the question of whether galactic fields are purely a primordial relic or were dynamically enhanced from a much smaller…

Astrophysics · Physics 2009-10-28 Sangjin Lee , Angela Olinto , Guenter Sigl

Context. The existence of magnetic fields in the circumgalactic medium (CGM) is largely unconstrained. Their detection is important as magnetic fields can have a significant impact on the evolution of the CGM and, in turn, the fields can…

Large-scale intergalactic magnetic fields may contain a mixture of galactic and cosmogenic contributions, that can be probed via observations of $\gamma$-ray "echo" - a delayed emission from electromagnetic cascades initiated by the highest…

High Energy Astrophysical Phenomena · Physics 2026-02-10 Ievgen Vovk

Very-high energy observations of blazars can be used to constrain the strength of the intergalactic magnetic field. A simplifying assumption which is often made is that of a magnetic field of constant strength composed by randomly oriented…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Chiara Caprini , Stefano Gabici

It is argued that if extragalactic magnetic fields are smaller than 2x10^{-12} G the flux of ultra-high energy photons of (a few)x10^{-1} eV cm^{-2}s^{-1}sr^{-1} predicted in the top-down models of UHE CR implies similar flux of the diffuse…

Astrophysics · Physics 2007-05-23 P. G. Tinyakov

We discuss the influence of extragalactic magnetic fields on the intensity of gamma-ray emission produced in electromagnetic cascades from ultra-high energy cosmic rays propagating in extragalactic space. Both cosmic rays and cascade…

High Energy Astrophysical Phenomena · Physics 2022-11-14 Anna Uryson

We discuss the magnetic field influence on diffuse gamma-ray emission from extragalactic electromagnetic cascades initiated by ultra-high energy cosmic rays. Regions in space vary considerably in field strength: it is possibly of 10^(-12) G…

High Energy Astrophysical Phenomena · Physics 2023-10-16 A. Uryson

We propose a method of measurement of extragalactic magnetic fields in observations of TeV gamma-rays from distant blazars. Multi-TeV gamma-rays are emitted by these sources in narrow jet with opening angle of few degrees. These primary…

Astrophysics · Physics 2008-11-26 A. Neronov , D. V. Semikoz

We study the properties of magnetic fields in the circumgalactic medium (CGM) of $z<1$ galaxies by correlating Faraday rotation measures of $\sim 1,000$ high-redshift radio sources with the foreground galaxy number density estimated from…

Astrophysics of Galaxies · Physics 2020-06-24 Ting-Wen Lan , J. Xavier Prochaska

A recent article from the Pierre Auger Collaboration links the direction of charged cosmic rays to possible extragalactic sites of emission. The correlation of the direction of such particles with the direction of the emitter allows…

Astrophysics · Physics 2008-11-26 Alessandro De Angelis , Massimo Persic , Marco Roncadelli
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