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Related papers: Slow diffusion around pulsar $\gamma$-ray halos an…

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It was suggested that the $\gamma$-ray halo around Geminga might not be interpreted by slow-diffusion. If the ballistic regime of electron/positron propagation is considered, the Geminga halo may be explained even with a large diffusion…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Li-Zhuo Bao , Kun Fang , Xiao-Jun Bi , Sheng-Hao Wang

The positron excess in cosmic rays has stimulated a lot of interests in the last decade. The dark matter origin of the extra positrons has attracted great attention. However, the $\gamma$-ray search set very stringent constraints on the…

High Energy Astrophysical Phenomena · Physics 2024-11-07 Xing-Jian Lv , Xiao-Jun Bi , Kun Fang , Peng-Fei Yin , Meng-Jie Zhao

The HAWC Collaboration has reported the detection of an extended $\gamma$-ray emission around the Geminga and Monogem pulsars of a few degree extension. Very recently, the LHAASO Collaboration released also the data for an extended…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Sarah Recchia , Mattia Di Mauro , Felix A. Aharonian , Luca Orusa , Fiorenza Donato , Stefano Gabici , Silvia Manconi

Pulsar halos are extended gamma-ray structures generated by electrons and positrons escaping from pulsar wind nebulae (PWNe), considered a new class of gamma-ray sources. They are ideal indicators for cosmic-ray propagation in localized…

High Energy Astrophysical Phenomena · Physics 2022-09-28 Kun Fang

The slow particle diffusion in pulsar halos, inferred from TeV gamma-ray surface brightness profiles, is attributed to cross-field diffusion under the anisotropic diffusion model. This model assumes sub-Alfv\'enic interstellar turbulence in…

High Energy Astrophysical Phenomena · Physics 2025-07-17 Kai Yan , Sha Wu , Ruo-Yu Liu

Pulsars are factories of relativistic electrons and positrons that propagate away from the pulsar, permeating later our Galaxy. The acceleration and propagation of these particles are a matter of intense debate. In the last few years, we…

High Energy Astrophysical Phenomena · Physics 2022-02-15 R. López-Coto , E. de Oña Wilhelmi , F. Aharonian , E. Amato , J. Hinton

Extended gamma-ray emission, interpreted as halos formed by the inverse-Compton scattering of ambient photons by electron-positron pairs, is observed toward a number of middle-aged pulsars. The physical origin and actual commonness of the…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Pierrick Martin , Alexandre Marcowith , Luigi Tibaldo

The recent HAWC observations of very-high-energy $\gamma$-ray halo around Geminga and Monogem indicate a very slow diffusion of cosmic rays, which results in tiny contribution of positrons from these two pulsars to the local flux. This…

High Energy Astrophysical Phenomena · Physics 2018-08-15 Kun Fang , Xiao-Jun Bi , Peng-Fei Yin , Qiang Yuan

Using pulsar accelerations, we identify and constrain the properties of a dark matter sub-halo in the Galaxy for the first time from analyzing the acceleration field of binary and solitary pulsars. Our MCMC calculations show that this…

Astrophysics of Galaxies · Physics 2025-12-04 Sukanya Chakrabarti , Philip Chang , Stefano Profumo , Peter Craig

Small-scale dark matter structure within the Milky Way is expected to affect pulsar timing. The change in gravitational potential induced by a dark matter halo passing near the line of sight to a pulsar would produce a varying delay in the…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Hamish A. Clark , Geraint F. Lewis , Pat Scott

In this work we use the newly reported Boron-to-Carbon ratio (B/C) from AMS-02 and the time-dependent proton fluxes from PAMELA and AMS-02 to constrain the source and propagation parameters of cosmic rays in the Milky Way. A linear…

High Energy Astrophysical Phenomena · Physics 2017-05-03 Qiang Yuan , Su-Jie Lin , Kun Fang , Xiao-Jun Bi

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

TeV Halos, extended regions of TeV gamma-ray emission around middle-aged pulsars, have recently been established as a new source class in gamma-ray astronomy. These halos have been attributed to relativistic electrons and positrons that…

Here I summarize constraints on the nature of the dark matter halos of field galaxies that have been obtained from the most recent investigations of (i) weak galaxy-galaxy lensing and (ii) the dynamics of satellite galaxies in orbit about…

Astrophysics · Physics 2009-11-10 Tereasa G. Brainerd

We study the vertical stellar distribution of the Milky Way thin disk in detail with particular focus on the outer disk. We treat the galactic disk as a gravitationally coupled, three-component system consisting of stars, atomic hydrogen…

Astrophysics of Galaxies · Physics 2018-10-03 Suchira Sarkar , Chanda J Jog

Observations of the TeV halos associated with nearby pulsars indicate that these objects inject significant fluxes of very high-energy electron-positrons pairs into the interstellar medium (ISM), thereby likely providing the dominant…

High Energy Astrophysical Phenomena · Physics 2023-02-17 Olivia Meredith Bitter , Dan Hooper

We study the annihilating dark matter contribution to the extra-galactic diffuse gamma-ray background spectrum, motivated by the recent observations of cosmic-ray positron/electron anomalies. The observed diffuse gamma-ray flux provides…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Masahiro Kawasaki , Kazunori Kohri , Kazunori Nakayama

Here we review our current knowledge on diffuse gamma-rays from galactic halos. Estimates of the relative contribution of the various emission processes at low and high latitudes are compared to the data over 6 decades in energy. The…

Astrophysics · Physics 2007-05-23 M. Pohl

We make a detailed analysis of the indirect diffuse gamma-ray signals from dark matter annihilation in the Galaxy. We include the prompt emission, as well as the emission from inverse Compton scattering whenever the annihilation products…

High Energy Astrophysical Phenomena · Physics 2012-11-14 Steve Blanchet , Julien Lavalle

The AMS-02 experiment is measuring the high energy charged cosmic rays with unprecedented accuracy. We explore the possibility of determining the cosmic-ray propagation models using the AMS-02 data $alone$. A global Bayesian analysis of the…

High Energy Physics - Phenomenology · Physics 2015-09-30 Hong-Bo Jin , Yue-Liang Wu , Yu-Feng Zhou
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