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Related papers: Constraining the Thickness of the Galactic Halo th…

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In our previous work, we have investigated Galactic cosmic ray (GCR) spectra and anisotropy from 100 GeV to PeV, under anisotropic propagation model with axisymmetric distributed galactic sources. Numerous observational evidence have…

High Energy Astrophysical Phenomena · Physics 2024-12-24 Aifeng Li , Zhaodong Lv , Wei Liu , Yiqing Guo , Fangheng Zhang

The existence of the cosmic ray Halo in our Galaxy has been discussed for more than half a century. If it is real it could help to explain some puzzling features of the cosmic ray flux: its small radial gradient, nearly perfect isotropy and…

Astrophysics of Galaxies · Physics 2015-06-19 Anatoly Erlykin , Arnold Wolfendale

As a basic characteristic of cosmic ray (CR) propagation, the diffusive halo can advance our understanding of many CR-related studies and indirect dark matter. The method to derive the halo size usually has degeneracy problems thus affected…

High Energy Astrophysical Phenomena · Physics 2021-10-27 Yu-Hua Yao , Bing-Qiang Qiao , Wei Liu , Qiang Yuan , Hong-Bo Hu , Xiao-Jun Bi , Chao-Wen Yang , Yi-Qing Guo

We propose a data-driven approach to reconstruct the all-sky distribution of the dispersion measure contribution from the Galactic halo ($\mathrm{DM_{halo}}$) through a spherical harmonic expansion, enabling an investigation of its possible…

Astrophysics of Galaxies · Physics 2026-01-07 Yang Liu , Bao Wang , Puxun Wu , Jun-Jie Wei , Xue-Feng Wu

The anisotropy of cosmic rays (CRs) in the solar vicinity is generally at- tributed to the CR streaming due to the discrete distribution of CR sources or local magnetic field modulation. Recently, the two dimensional large scale CR…

Astrophysics of Galaxies · Physics 2012-04-17 Xiao-bo Qu , Yi Zhang , Liang Xue , Cheng Liu , Hong-bo Hu

We investigate the effects of stochasticity in the spatial and temporal distribution of supernova remnants on the anisotropy of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Pasquale Blasi , Elena Amato

We show that host cold dark matter (CDM) haloes cluster in a manner that depends upon the anisotropy and planarity of their subhaloes, indicating an environmental dependence to subhalo anisotropy and planarity. The spatial distributions of…

Astrophysics of Galaxies · Physics 2026-04-15 Nathaniel P. Johnson , Andrew R. Zentner

The anisotropy parameter $\beta$ characterizes the extent to which orbits in stellar systems are predominantly radial or tangential, and is likely to constrain, for the stellar halo of the Milky Way, scenarios for its formation and…

Astrophysics of Galaxies · Physics 2020-08-06 Sarah A. Bird , Xiang-Xiang Xue , Chao Liu , Juntai Shen , Chris Flynn , Chengqun Yang

We analyze the anisotropy profile of the Milky Way's smooth, diffuse stellar halo using SDSS/SEGUE blue horizontal branch stars and SDSS/SEGUE and LAMOST K giants. These intrinsically luminous stars allow us to probe the halo to…

Astrophysics of Galaxies · Physics 2021-10-04 Sarah A. Bird , Xiang-Xiang Xue , Chao Liu , Juntai Shen , Chris Flynn , Chengqun Yang , Gang Zhao , Hai-Jun Tian

We develop a flexible set of action-based distribution functions (DFs) for stellar haloes. The DFs have five free parameters, controlling the inner and outer density slope, break radius, flattening and anisotropy respectively. The DFs…

Astrophysics of Galaxies · Physics 2015-09-30 A. A. Williams , N. W. Evans

The stellar halo of the Milky Way is known to have a highly lumpy structure due to the presence of tidal debris and streams accreted from the satellite galaxies. The abundance and distribution of these substructures can provide a wealth of…

Astrophysics of Galaxies · Physics 2022-10-21 Biswajit Pandey

The harmonic analysis of anisotropy of Ultra High Energy Cosmic Rays is performed for the Dark Matter halo model. In this model the relic superheavy particles comprise part of the Dark Matter and are concentrated in the Galactic halo. The…

Astrophysics · Physics 2016-08-30 V. Berezinsky , A. Mikhailov

Modeling the Milky Way stellar halo requires well-determined density and velocity anisotropy profiles. However, it has been challenging to gather a large sample of stars with six-dimensional data that extend beyond 40 kpc to map the outer…

The spatial-dependent propagation model has been successfully used to explain diverse observational phenomena, including the spectral hardening of cosmic-ray nuclei above $200$ GV, the large-scale dipole anisotropy and the diffusive gamma…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Zhen Tian , Wei Liu , Bo Yang , Xue-Dong Fu , Hai-Bo Xu , Yu-hua Yao , Yi-Qing Guo

We propose a new method for measuring the spatial density distribution of the stellar halo of the Milky Way. Our method is based on a pairwise statistic of the distribution of stars on the sky, the angular two-point correlation function…

Astrophysics of Galaxies · Physics 2023-08-09 Anda Chen , Zhigang Li , Yougang Wang , Yan Gong , Xuelei Chen , Richard J. Long

We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of the cosmic infall: we measure the flows at…

Astrophysics · Physics 2009-11-10 Dominique Aubert , Christophe Pichon , Stephane Colombi

Recently studies of the dipole anisotropy in the arrival directions of Galactic cosmic rays indicate that the TeV-PeV dipole anisotropy amplitude is not described by a simple power law, moreover a rapid phase change exists at an energy of…

High Energy Astrophysical Phenomena · Physics 2019-01-03 Xiaobo Qu

Using the SIMBA, EAGLE, and IllustrisTNG-100 galaxy formation simulations, we examine the anisotropy of the satellite distribution and its dependencies on central galaxies, host halos, and cosmic filaments. We find that in all simulations…

Astrophysics of Galaxies · Physics 2026-05-01 Zhuoming Zhang , Weiguang Cui , Yun Chen , Romeel Davé , Katarina Kraljic

Our goal is to recover the Galactic Halo spatial density by means of field stars. To this aim, we apply a new technique to the Capodimonte Deep Field (OACDF, Alcala' et al. 2004), as a pilot study in view of the VLT Survey Telescope (VST)…

Astrophysics · Physics 2009-11-11 M. Cignoni , V. Ripepi , M. Marconi , J. M. Alcala' , M. Capaccioli , M. Pannella , R. Silvotti

We investigate the dynamical response of dispersion-dominated halo populations to a rotating galactic bar, focusing on how the underlying halo phase space distribution function (DF), and in particular the orbital anisotropy, shapes resonant…

Astrophysics of Galaxies · Physics 2026-05-29 Paula Gherghinescu , Francesca Fragkoudi , Alis Deason
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