English
Related papers

Related papers: Constraining anisotropic diffusion between Geminga…

200 papers

Low-frequency radio observations of diffuse synchrotron radiation offer a unique vantage point for investigating the intricate relationship between gas and magnetic fields in the formation of structures within the Galaxy, spanning from the…

Astrophysics of Galaxies · Physics 2024-05-29 Andrea Bracco , Marco Padovani , Daniele Galli

The bulk of the diffuse galactic gamma-ray emission above a few tens of GeV has been conventionally ascribed to the decay of neutral pions produced in cosmic-ray interactions with interstellar matter. Cosmic-ray electrons may, however, make…

Astrophysics · Physics 2008-11-26 T. A. Porter , R. J. Protheroe

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

Using fully kinetic 3D simulations, the reconnection dynamics of asymmetric current sheets are examined at the Earth's magnetopause. The plasma parameters are selected to model MMS magnetopause diffusion region crossings with guide fields…

First results of a Cosmic Microwave Background (CMB) anisotropy experiment conducted at the Observatorio del Teide (Tenerife, Spain) are presented. The instrument is a four channel (3.1, 2.1, 1.3 and 1.1 mm) $^3$He bolometer system coupled…

Recent observations of the diffuse Galactic gamma-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the…

High Energy Astrophysical Phenomena · Physics 2017-08-17 G. Morlino , M. D'Angelo , P. Blasi , E. Amato

Both cosmic shear and cosmological gamma-ray emission stem from the presence of Dark Matter (DM) in the Universe: DM structures are responsible for the bending of light in the weak lensing regime and those same objects can emit gamma-rays,…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 S. Camera , M. Fornasa , N. Fornengo , M. Regis

Measuring the anisotropy of the arrival direction distribution of cosmic rays provides important information on the propagation mechanisms and the identification of their sources. In fact, the flux of cosmic rays is thought to be dependent…

High Energy Astrophysical Phenomena · Physics 2013-09-25 YBJ Collaboration

Based on the diffusion-halo model for cosmic-ray (CR) propagation, including stochastic reacceleration due to collisions with hydromagnetic turbulence, we study the behavior of the electron component and the diffuse $\gamma$-rays…

High Energy Astrophysical Phenomena · Physics 2011-01-27 T. Shibata , T. Ishikawa , S. Sekiguchi

The recently discovered soft gamma-ray emission from the anomalous X-ray pulsar 1E 1841-045 has a luminosity L_g ~ 10^{36} ergs/s. This luminosity exceeds the spindown power by three orders of magnitude and must be fed by an alternative…

Astrophysics · Physics 2009-11-10 C. Thompson , A. M. Beloborodov

The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. de Boer

As recently shown, Fermi-LAT measurements of the diffuse gamma-ray emission from the Galaxy favor the presence of a smooth softening in the primary cosmic-ray spectrum with increasing Galactocentric distance. This result can be interpreted…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Daniele Gaggero , Dario Grasso , Antonio Marinelli , Alfredo Urbano , Mauro Valli

Very-high-energy (VHE; $E \gtrsim 100$ GeV) gamma rays are expected to experience strong attenuation during cosmological propagation due to electron-positron pair production on the extragalactic background light (EBL). Recent observations…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Longhua Qin , Jiancheng Wang , Chuyuan Yang , Huaizhen Li , Quangui Gao , Ju Ma , Ao Wang , Weiwei Na , Ming Zhou , Zunli Yuan , Chunxia Gu , Guangbo Long

Recent analyses of the anisotropy of cosmic rays at $10^{18}$ eV (the AGASA and SUGAR data) show significant excesses from regions close to the Galactic Centre and Cygnus. Our aim is to check whether such anisotropies can be caused by…

Astrophysics · Physics 2008-11-26 W. Bednarek , M. Giller , M. Zielinska

High-energy (HE) and very high-energy (VHE) gamma-ray observations from the Galactic center (GC) detected extended emission correlated with the morphology of the central molecular zone (CMZ). Emission in both bands is expected to be…

High Energy Astrophysical Phenomena · Physics 2024-10-01 Andrés Scherer , Jorge Cuadra

Pulsar halos (also termed 'TeV halo') are a new class of $\gamma$-ray sources in Galaxy, which manifest as extended $\gamma$-ray emission around middle-age pulsars, as discovered around the Geminga pulsar, the Monogem pulsar and…

High Energy Astrophysical Phenomena · Physics 2024-02-01 Qi-Zuo Wu , Chao-Ming Li , Xuan-Han Liang , Chong Ge , Ruo-Yu Liu

The very high energy (VHE) emission of the Central Molecular Zone (CMZ) is rarely modelled in 3D. Most approaches describe the morphology in 1D or simplify the diffusion to the isotropic case. In this work we show the impact of a realistic…

High Energy Astrophysical Phenomena · Physics 2024-04-19 J. Dörner , J. Becker Tjus , P. -S. Blomenkamp , H. Fichtner , A. Franckowiak , E. M. Zaninger

Dark matter annihilation in galactic substructure would imprint characteristic angular signatures on the all-sky map of the diffuse gamma-ray background. We study the gamma-ray background anisotropy due to the subhalos and discuss…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-21 Shin'ichiro Ando

We investigate the temporal and spectral correlations between flux and anisotropy fluctuations of TeV-band cosmic rays in the light of recent data taken with IceCube. We find that for a conventional distribution of cosmic-ray sources the…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Martin Pohl , David Eichler

Isotropic diffusion models for Galactic cosmic ray transport put tight constraints on the maximum convection velocity in the halo. For a half halo height of 4 kpc the maximum convection speed is limited to 40 km/s in the halo, since…

Astrophysics of Galaxies · Physics 2009-10-13 Iris Gebauer , Wim de Boer