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

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Optical and near-IR observations of the halos of disk galaxies and blue compact galaxies have revealed a very red spectral energy distribution, which cannot easily be reconciled with a normal, metal-poor stellar population like that in the…

Astrophysics · Physics 2008-11-26 E. Zackrisson , N. Bergvall , G. Ostlin , G. Micheva , M. Leksell

Diffusive TeV gamma-ray emissions have been recently discovered extending beyond the pulsar wind nebulae of a few middle-aged pulsars, implying that energetic electron/positron pairs are escaping from the pulsar wind nebulae and radiating…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Ruo-Yu Liu

A novel phenomenon among the recently observed Geminga pulsar halo is the presence of distinct radiation morphology at high energies, while no extended radiation is detected in the 10-500 GeV energy band within a $40\degree\times40\degree$…

High Energy Astrophysical Phenomena · Physics 2025-09-03 Lin Nie , Yu-Hai Ge , Yi-Qing Guo , Si-Ming Liu

We report calculations of cosmic-ray proton, nuclei, antiproton, electron and positron energy spectra within a "two-halo model" of diffusive transport. The two halos represent a simple, physically consistent generalization of the standard…

High Energy Astrophysical Phenomena · Physics 2015-10-20 Nicola Tomassetti

Geminga pulsar is surrounded by a multi-TeV $\gamma$-ray halo radiated by the high energy electrons and positrons accelerated by the central pulsar wind nebula (PWN). The angular profile of the $\gamma$-ray emission reported by HAWC…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Kun Fang , Xiao-Jun Bi , Peng-Fei Yin

Galactic Cosmic-ray (CR) transport parameters are usually constrained by the boron-to-carbon ratio. This procedure is generically plagued with degeneracies between the diffusion coefficient and the vertical extent of the Galactic magnetic…

High Energy Astrophysical Phenomena · Physics 2015-01-23 Julien Lavalle , David Maurin , Antje Putze

Detailed observation by the High-Altitude Water Cerenkov Observatory of the regions within about 20 pc of the nearby Geminga and PSR B0656+14 pulsars have suggested the need for the diffusion coefficient of 10-100 TeV leptons yielding the…

High Energy Astrophysical Phenomena · Physics 2018-07-20 J J Quenby

In this paper we review the main and the most recent evidence for the presence of a core radius in the distribution of the dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an…

Astrophysics · Physics 2007-05-23 Paolo Salucci , Annamaria Borriello

Observations of the vicinity of a variety of galactic gamma-ray sources have indicated a local suppression of diffusivity of cosmic rays by up to three orders of magnitude. However, the impact of these low-diffusion zones on \emph{global}…

High Energy Astrophysical Phenomena · Physics 2023-05-18 Hanno Jacobs , Philipp Mertsch , Vo Hong Minh Phan

We introduce a new technique to constrain the line-of-sight integrated electron density of our Galactic halo $\text{DM}_\text{MW,halo}$ through analysis of the observed dispersion measure distributions of pulsars $\text{DM}_\text{pulsar}$…

Astrophysics of Galaxies · Physics 2020-06-09 E. Platts , J. Xavier Prochaska , Casey J. Law

Recently, a few-degrees extended $\gamma$-ray halo in the direction of Geminga pulsar has been detected by HAWC, Milagro and Fermi-LAT. These observations can be interpreted with positrons ($e^+$) and electrons ($e^-$) accelerated by…

High Energy Astrophysical Phenomena · Physics 2021-12-07 Mattia Di Mauro , Silvia Manconi , Fiorenza Donato

Diffuse gamma-ray emission (DGE) has been discovered over the Galactic disk in the energy range from sub-GeV to sub-PeV. While it is believed to be dominated by the pionic emission of cosmic ray (CR) hadrons via interactions with…

High Energy Astrophysical Phenomena · Physics 2023-05-18 Kai Yan , Ruo-Yu Liu

We review the most recent evidence for the amazing properties of the density distribution of dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an universal profile which can be…

Astrophysics · Physics 2007-05-23 P. Salucci , A. Borriello

Cosmic-ray positrons have long been considered a powerful probe of dark matter annihilation. In particular, myriad studies of the unexpected rise in the positron fraction have debated its dark matter or pulsar origins. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2022-01-07 Isabelle John , Tim Linden

The implications of the first AMS-02 $\bar p/p$ data for the propagation of cosmic rays and the properties of dark matter (DM) are discussed. Using various diffusive re-acceleration (DR) propagation models, one can derive very conservative…

High Energy Physics - Phenomenology · Physics 2015-08-28 Hong-Bo Jin , Yue-Liang Wu , Yu-Feng Zhou

The dark matter distribution in dwarf galaxies holds a wealth of information on the fundamental properties and interactions of the dark matter particle. In this paper, we study whether ultralight bosonic dark matter is consistent with the…

Astrophysics of Galaxies · Physics 2023-01-26 Isabelle S. Goldstein , Savvas M. Koushiappas , Matthew G. Walker

Cosmic-ray (CR) positrons are relatively rare due to their secondary origin and thus sensitive to exotic contributions. Primordial black holes (PBHs) with masses above $\sim 5\times10^{14}\,\mathrm{g}$ can be stable sources of CR positrons…

High Energy Physics - Phenomenology · Physics 2025-04-08 Jia-Zhi Huang , Yu-Feng Zhou

We derive the mass model of the Milky Way (MW) using a cored dark matter (DM) halo profile and recent data. The method used consists in fitting a spherically symmetric model of the Galaxy with a Burkert DM halo profile to available data: MW…

Astrophysics of Galaxies · Physics 2015-06-15 Fabrizio Nesti , Paolo Salucci

We present robust constraints from the Sloan Digital Sky Survey (SDSS) on the shape and distribution of the dark matter halo within the Milky Way (MW). Using the number density distribution and kinematics of SDSS halo stars, we probe the…

A scenario for achieving a low velocity dispersion for the galaxy [KKS 2000]04 (aka NGC 1052-DF2) and similar galaxies is presented. A progenitor halo corresponding to a $z=0$ halo of mass $\sim 5\times 10^{10}\; \textrm{M}_\odot$ and a low…

Astrophysics of Galaxies · Physics 2020-04-22 Adi Nusser