Results 31 to 40 of about 298 (165)

Constraining axion-like particles with the diffuse gamma-ray flux measured by the Large High Altitude Air Shower Observatory

European Physical Journal C: Particles and Fields, 2022
The detection of very high-energy neutrinos by IceCube experiment supports the existence of a comparable gamma-ray counterpart from the same cosmic accelerators. Under the likely assumption that the sources of these particles are of extragalactic origin,
Leonardo Mastrototaro, Pierluca Carenza, Marco Chianese, Damiano F. G. Fiorillo, Gennaro Miele, Alessandro Mirizzi, Daniele Montanino   +6 more
doaj   +1 more source

Magnetic fields in extragalactic jets

The Astrophysical Journal, 1987
Observations indicate that jets (i.e., charged particle beams) are emitted from the central black hole sources of active galactic nuclei and quasars. Magnetic fields are produced in e(-)-p or e(-)-e(+)-p jets when electrons (and positrons) are slowed with respect to protons in the jets. Interaction with an ambient interstellar gas or external radiation
openaire   +1 more source

Simulations of extragalactic magnetic fields and of their observables [PDF]

Classical and Quantum Gravity, 2017
The origin of extragalactic magnetic fields is still poorly understood. Based on a dedicated suite of cosmological magneto-hydrodynamical simulations with the ENZO code we have performed a survey of different models that may have caused present-day magnetic fields in galaxies and galaxy clusters. The outcomes of these models differ in cluster outskirts,
Vazza, F., BrÃ1⁄4ggen, M., Gheller, C., Hackstein, S., Wittor, D., Hinz, P. M.   +5 more
openaire   +4 more sources

Constraining the Astrophysical Origin of Intergalactic Magnetic Fields

The Astrophysical Journal
High-energy photons can produce electron–positron pairs upon interacting with the extragalactic background light. These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic ...
J. Tjemsland, M. Meyer, F. Vazza
doaj   +1 more source

Magnetic Field of Molecular Gas Measured with the Velocity Gradient Technique. II. Curved Magnetic Field in kpc-scale Bubble of NGC 628

The Astrophysical Journal
We report the detection of the ordered alignment between the magnetic field and kpc-scale bubbles in the nearby spiral galaxy, NGC 628. Applying the Velocity Gradient Technique on CO spectroscopic data from the ALMA-PHANGS, the magnetic field of NGC 628 ...
Mengke Zhao, Jianjun Zhou, Willem A. Baan, Yue Hu, A. Lazarian, Xindi Tang, Jarken Esimbek, Yuxin He, Dalei Li, Weiguang Ji, Zhengxue Chang, Kadirya Tursun   +11 more
doaj   +1 more source

UHECRs Propagation and Their Multimessengers: Upper Limits and the Impact of the Extragalactic Magnetic Field

The Astrophysical Journal
The detection of high-energy astrophysical multimessengers establishes a connection between ultra-high-energy cosmic rays (UHECRs) and powerful cosmic accelerators.
Rodrigo Sasse, Rubens Costa Jr., Adriel G.B. Mocellin, Carlos H. Coimbra-Araujo, R. C. Dos Anjos   +4 more
doaj   +1 more source

Magnetic fields of extragalactic radio sources: Testing cosmological models [PDF]

Astronomy Letters, 2006
Based on the synchrotron radiation mechanism with self-absorption, we estimate the magnetic fields of compact (∼0 . ″ 001) structures of radio galaxies. Using a model radial dependence of the magnetic field, we estimate the field strength near the event horizon of a supermassive black hole. The latter
Yu. N. Gnedin, M. Yu. Piotrovich
openaire   +1 more source

Magnetic fields in extragalactic radio sources

The Astrophysical Journal, 1981
Distributions of total intensity and linear polarization have been calculated for synchrotron radiation from a variety of magnetic fields which may occur in extragalactic radio sources, assuming that the energy distributions of radiating electrons are uniform and isotropic. Analytical solutions are derived for helical and transverse self-similar fields
openaire   +1 more source

GRB 221009A: A Light Dark Matter Burst or an Extremely Bright Inverse Compton Component?

The Astrophysical Journal, 2023
Gamma-ray bursts (GRBs) have been considered as potential very high energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets.
M. M. González, D. Avila Rojas, A. Pratts, S. Hernández-Cadena, N. Fraija, R. Alfaro, Y. Pérez Araujo, J. A. Montes   +7 more
doaj   +1 more source

Ultrahigh energy heavy nuclei propagation in extragalactic magnetic fields

Physical Review D, 2002
We extend existing work on the propagation of ultra-high energy cosmic rays in extragalactic magnetic fields to a possible component of heavy nuclei, taking into account photodisintegration, pion production, and creation of e+e- pairs. We focus on the influence of the magnetic field on the spectrum and chemical composition of observed ultra-high energy
Bertone, Gianfranco, Isola, Claudia, Lemoine, Martin, Sigl, Guenter   +3 more
openaire   +3 more sources