scholarly journals Fitting electron spectrum from AMS-02 by pulsar electrons

2021 ◽  
Vol 2145 (1) ◽  
pp. 012003
Author(s):  
Kritaporn Butsaracom ◽  
Brandon Khan Cantlay ◽  
Maneenate Wechakama
Keyword(s):  
Cosmic Ray ◽  
Total Spin ◽  
Short Length ◽  
Propagation Model ◽  
Background Model ◽  
Secondary Electrons ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Electron Propagation ◽  
The Magnetic Field

Abstract In this work, we aim to explain the latest data of cosmic-ray electrons from AMS-02 by an electron background model and pulsar electrons. We consider an electron background model which includes primary and secondary electrons. We assume that pulsars are major sources of the electron excess. Since electrons easily lose their energy through the interstellar radiation field and the magnetic field via inverse Compton scattering and synchrotron radiation, respectively, they propagate in a short length. We adopt nearby pulsar data in the distance of 1 kpc from the Australia Telescope National Facility (ATNF) pulsar catalogue. By using a Green’s function of an electron propagation model, we then fit pulsar parameters (i.e. the spectral index, the fraction of the total spin-down energy and the cutoff energy) for several cases of a single pulsar. With a combination of the electron background model, several cases of pulsar spectrum are able to explain the electron excess.

scholarly journals A MODEL-INDEPENDENT METHOD TO STUDY DARK MATTER INDUCED LEPTONS AND GAMMA RAYS

2012 ◽  
Vol 27 (35) ◽  
pp. 1250206 ◽  
Author(s):  
MINGXING LUO ◽  
LIUCHENG WANG ◽  
GUOHUAI ZHU
Keyword(s):  
Dark Matter ◽  
Compton Scattering ◽  
Gamma Rays ◽  
Particle Physics ◽  
Cosmic Ray ◽  
Propagation Model ◽  
Strong Constraint ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Model Independent

By using recent data, we directly determine the dark matter (DM)-induced e± spectrum at the source from experimental measurements at the earth, without reference to specific particle physics models. The DM-induced gamma rays emitted via inverse Compton scattering are then obtained in a model-independent way. However, the results depend on the choice of the astrophysical e± background, which is not reliably known. Nevertheless, we calculate, as an illustration, the fluxes of gamma rays from the Fornax cluster in the decaying DM scenario with various astrophysical e± backgrounds. Without any assumptions on details of the DM model, the predictions turn out to be either in disagreement with or only marginally below the upper limits measured recently by the Fermi-LAT Collaboration. In addition, these DM-induced ICS gamma rays in the GeV range are shown to be almost independent of choices of cosmic ray propagation model and of DM density profile, when a given astrophysical e± background is assumed. This provides a strong constraint on decaying DM scenario as the gamma rays may be produced in other processes besides inverse Compton scattering, such as the bremsstrahlung and neutral pion decays.

Can Galactic γ-Ray Background be due to Superposition of γ-Rays from Millisecond Pulsars?

1998 ◽  
Vol 188 ◽  
pp. 273-274
Author(s):  
V.B. Bhatia ◽  
S. Mishra ◽  
N. Panchapakesan
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Diffuse Radiation ◽  
High Energy ◽  
Molecular Gas ◽  
Inverse Compton Scattering ◽  
High Energy Electrons ◽  
Inverse Compton ◽  
Γ Rays ◽  
Γ Ray

The SAS 2 and COS B observations have established the existence of diffuse γ-rays in our Galaxy in various energy ranges. The diffuse radiation is attributed to the interaction of cosmic ray nuclei and electrons with the particles of interstellar atomic and molecular gas (via the decay of pions and bremsstrahlung, respectively). Inverse Compton scattering of interstellar photons by the high energy electrons of cosmic rays may also be contributing to this background. In addition some contribution may come from discrete sources of γ-rays.

scholarly journals G0.173−0.42: an X-ray and radio magnetized filament near the galactic centre

2020 ◽  
Vol 500 (3) ◽  
pp. 3142-3150
Author(s):  
F Yusef-Zadeh ◽  
M Wardle ◽  
C Heinke ◽  
I Heywood ◽  
R Arendt ◽  
...  
Keyword(s):  
Galactic Centre ◽  
Physical Interaction ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Structural Details ◽  
Field Lines ◽  
The Magnetic Field ◽  
Relativistic Particles

ABSTRACT The detection of an X-ray filament associated with the radio filament G0.173–0.42 adds to four other non-thermal radio filaments with X-ray counterparts, amongst the more than 100 elongated radio structures that have been identified as synchrotron-emitting radio filaments in the inner couple of degrees of the Galactic centre. The synchrotron mechanism has also been proposed to explain the emission from X-ray filaments. However, the origin of radio filaments and the acceleration sites of energetic particles to produce synchrotron emission in radio and X-rays remain mysterious. Using MeerKAT, VLA, Chandra, WISE, and Spitzer, we present structural details of G0.173–0.42 which consists of multiple radio filaments, one of which has an X-ray counterpart. A faint oblique radio filament crosses the radio and X-ray filaments. Based on the morphology, brightening of radio and X-ray intensities, and radio spectral index variation, we argue that a physical interaction is taking place between two magnetized filaments. We consider that the reconnection of the magnetic field lines at the interaction site leads to the acceleration of particles to GeV energies. We also argue against the synchrotron mechanism for the X-ray emission due to the short ∼30 yr lifetime of TeV relativistic particles. Instead, we propose that the inverse Compton scattering mechanism is more likely to explain the X-ray emission by upscattering of seed photons emitted from a 106  L⊙ star located at the northern tip of the X-ray filament.

High-energy γ rays of cosmic origin

1968 ◽  
Vol 46 (10) ◽  
pp. S484-S487 ◽  
Author(s):  
K. C. Anand ◽  
R. R. Daniel ◽  
S. A. Stephens
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
X Rays ◽  
Inverse Compton Scattering ◽  
Upper Limits ◽  
Inverse Compton ◽  
Geomagnetic Cutoff ◽  
Γ Rays ◽  
Residual Air ◽  
Cosmic Origin

A stack of nuclear emulsions flown over Hyderabad (vertical geomagnetic cutoff rigidity 16.9 GV), India, under 6 g/cm2 of residual air has been used to set upper limits to the flux of γ rays of cosmic origin. The integral flux values obtained are 13 × 10−4, 6 × 10−4, 2.6 × 10−4, 1.4 × 10−4, 0.6 × 10−4, and 0.3 × 10−4 photons (em2 s sr)−1 for energies greater than 50 MeV, 100 MeV, 2 GeV, 5 GeV, 10 GeV, and 50 GeV respectively. Using these data and those of Kraushaar et al. (1965), it seems unlikely that cosmic-ray collisions in meta-galactic space can be an important source of electrons needed to explain the finite flux of cosmic X rays as due to the inverse Compton scattering of these electrons with photons of the universal blackbody radiation at 3 °K; such collisions would predict a flux of γ rays much in excess of the upper limits obtained in the energy region 50–100 MeV.

scholarly journals ICS as a Limiting Factor for Electron Energies in Pulsar Magnetospheres

2000 ◽  
Vol 177 ◽  
pp. 469-472
Author(s):  
Rodrigo Supper
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Field Strength ◽  
Limiting Factor ◽  
Polar Cap ◽  
Analytical Treatment ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Cap Model ◽  
The Magnetic Field

AbstractBased on the polar cap model, we investigated in the energy loss of accelerated electrons in a neutron star magnetosphere by inverse Compton scattering of thermal photospheric radiation. An analytical treatment is presented, which turns out ranges in the magnetic field strength and thermal temperature where ultrarelativistic electrons can not survive.

scholarly journals Detailed structure of the X-ray jet in 4C 19.44 (PKS1354+195)

2006 ◽  
Vol 2 (S238) ◽  
pp. 443-444
Author(s):  
D. A. Schwartz ◽  
D. E. Harris ◽  
H. Landt ◽  
A. Siemiginowska ◽  
E. S. Perlman ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Particle Density ◽  
Relativistic Particle ◽  
Particle Energy ◽  
Microwave Background ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Doppler Factor ◽  
The Magnetic Field

AbstractWe investigate the variations of the magnetic field, Doppler factor, and relativistic particle density along the jet of a quasar at z=0.72. We chose 4C 19.44 for this study because of its length and straight morphology. The 18 arcsec length of the jet provides many independent resolution elements in the Chandra X-ray image. The straightness suggests that geometry factors, although uncertain, are almost constant along the jet. We assume the X-ray emission is from inverse Compton scattering of the cosmic microwave background. With the aid of assumptions about jet alignment, equipartition between magnetic-field and relativistic-particle energy, and filling factors, we find that the jet is in bulk relativistic motion with a Doppler factor ≈ 6 at an angle no more than 10∘ to the line of sight over de-projected distances ≈ 150–600 kpc from the quasar, and with a magnetic field ≈10 μGauss.

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