scholarly journals Diffuse synchrotron emission from galactic cosmic ray electrons

2015 ◽  
Vol 2 ◽  
pp. 21-26 ◽  
Author(s):  
G. Di Bernardo ◽  
D. Grasso ◽  
C. Evoli ◽  
D. Gaggero
Keyword(s):  
Cosmic Ray ◽  
Diffuse Radiation ◽  
Source Distribution ◽  
Microwave Background ◽  
3 Dimensional ◽  
The Galaxy ◽  
Consistent Treatment ◽  
Galactic Cosmic Ray ◽  
First Time ◽  
Spiral Arm

Abstract. Synchrotron diffuse radiation (SDR) emission is one of the major Galactic components, in the 100 MHz up to 100 GHz frequency range. Its spectrum and sky map provide valuable measure of the galactic cosmic ray electrons (GCRE) in the relevant energy range, as well as of the strength and structure of the Galactic magnetic fields (GMF), both regular and random ones. This emission is an astrophysical sky foreground for the study of the Cosmic Microwave Background (CMB), and the extragalactic microwave measurements, and it needs to be modelled as better as possible. In this regard, in order to get an accurate description of the SDR in the Galaxy, we use – for the first time in this context – 3-dimensional GCRE models obtained by running the DRAGON code. This allows us to account for a realistic spiral arm pattern of the source distribution, demanded to get a self-consistent treatment of all relevant energy losses influencing the final synchrotron spectrum.

Some Astrophysical Implications of Recent Measurements on the Intensity of Cosmic-Ray Electrons

1968 ◽  
Vol 1 (3) ◽  
pp. 112-113 ◽  
Author(s):  
W.R. Webber
Keyword(s):  
Electron Spectrum ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
List Type ◽  
Secondary Electrons ◽  
The Earth ◽  
Thermal Radio Emission ◽  
The Galaxy ◽  
Electron Intensity ◽  
Spiral Arm

We have extended our recent measurements on the extraterrestrial cosmic ray electron spectrum, this spectrum now being determined over the energy range from ~15 MeV to 6 GeV. The extraterrestrial electron intensity between 15 MeV and 200 MeV can be determined unambiguously by studying the diurnal variation of these particles. We have also measured the effects of the 11-year solar modulation on the electrons, thus enabling the electron spectrum observed near the Earth to be extrapolated to the local region of the spiral arm. It is the purpose of this paper to relate these measurements to: (i) calculations of ‘secondary’ electrons produced by cosmic ray nuclei moving in the Galaxy; and(ii) the observations of non-thermal radio emission from disk components of the Galaxy.

scholarly journals Contribution of the Galactic centre to the local cosmic-ray flux

2018 ◽  
Vol 619 ◽  
pp. A12 ◽  
Author(s):  
Étienne Jaupart ◽  
Étienne Parizot ◽  
Denis Allard
Keyword(s):  
Galactic Disk ◽  
A Priori ◽  
Cosmic Ray ◽  
High Energy ◽  
Single Type ◽  
Galactic Centre ◽  
High Energy Particle ◽  
The Galaxy ◽  
Injection Power ◽  
Galactic Cosmic Ray

Context. Recent observations of unexpected structures in the Galactic cosmic ray (GCR) spectrum and composition, as well as growing evidence for episodes of intense dynamical activity in the inner regions of the Galaxy, call for an evaluation of the high-energy particle acceleration associated with such activity and its potential impact on the global GCR phenomenology. Aims. We investigate whether particles accelerated during high-power episodes around the Galactic centre can account for a significant fraction of the observed GCRs, or, conversely, what constraints can be derived regarding their Galactic transport if their contributions are negligible. Methods. Particle transport in the Galaxy is described with a two-zone analytical model. We solved for the contribution of a Galactic centre cosmic-Ray (GCCR) source using Green functions and Bessel expansion, and discussed the required injection power for these GCCRs to influence the global GCR phenomenology at Earth. Results. We find that, with standard parameters for particle propagation in the galactic disk and halo, the GCCRs can make a significant or even dominant contribution to the total CR flux observed at Earth. Depending on the parameters, such a source can account for both the observed proton flux and boron-to-carbon ratio (in the case of a Kraichnan-like scaling of the diffusion coefficient), or potentially produce spectral and composition features. Conclusions. Our results show that the contribution of GCCRs cannot be neglected a priori, and that they can influence the global GCR phenomenology significantly, thereby calling for a reassessement of the standard inferences from a scenario where GCRs are entirely dominated by a single type of sources distributed throughout the Galactic disk.

scholarly journals Galactic Anisotropy of Cosmic Ray Intensity Observed by an Air Shower Experiment

2006 ◽  
Vol 23 (3) ◽  
pp. 129-134
Author(s):  
Mahmud Bahmanabadi ◽  
Mehdi Khakian Ghomi ◽  
Farzaneh Sheidaei ◽  
Jalal Samimi
Keyword(s):  
Daily Variation ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Extensive Air Shower ◽  
Air Shower ◽  
The Earth ◽  
The Galaxy ◽  
Unidirectional Anisotropy ◽  
Galactic Cosmic Ray ◽  
Shower Array

AbstractWe have monitored multi-TeV cosmic rays by a small air shower array in Tehran (35°43′ N, 51°20′ E, 1200 m = 890 g cm−2). More than 1.1 × 106 extensive air shower events were recorded. These observations enabled us to analyse sidereal variation of the galactic cosmic ray intensity. The observed sidereal daily variation is compared to the expected variation which includes the Compton–Getting effect due to the motion of the earth in the Galaxy. In addition to the Compton–Getting effect, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms.

scholarly journals Neutrino flux from cosmic ray accelerators in the Cygnus spiral arm of the Galaxy

2007 ◽  
Vol 76 (6) ◽  
Author(s):  
Luis Anchordoqui ◽  
Francis Halzen ◽  
Teresa Montaruli ◽  
Aongus Ó Murchadha
Keyword(s):  
Neutrino Flux ◽  
Cosmic Ray ◽  
The Galaxy ◽  
Spiral Arm

Diffuse radiation from cosmic ray interactions in the galaxy

1993 ◽  
Vol 1 (3) ◽  
pp. 281-287 ◽  
Author(s):  
V.S. Berezinsky ◽  
T.K. Gaisser ◽  
F. Halzen ◽  
Todor Stanev
Keyword(s):  
Cosmic Ray ◽  
Diffuse Radiation ◽  
Cosmic Ray Interactions ◽  
The Galaxy

scholarly journals Publisher’s Note: Neutrino flux from cosmic ray accelerators in the Cygnus spiral arm of the Galaxy [Phys. Rev. D76, 067301 (2007)]

2008 ◽  
Vol 77 (6) ◽  
Author(s):  
Luis Anchordoqui ◽  
Francis Halzen ◽  
Teresa Montaruli ◽  
Aongus Ó Murchadha
Keyword(s):  
Neutrino Flux ◽  
Cosmic Ray ◽  
The Galaxy ◽  
Spiral Arm

scholarly journals Anisotropies and the Power Requirements for Galactic Cosmic Rays

1998 ◽  
Vol 15 (2) ◽  
pp. 208-210 ◽  
Author(s):  
R. W. Clay ◽  
M.-A. McDonough ◽  
A. G. K. Smith ◽  
B. R. Dawson
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
The Galaxy ◽  
Unidirectional Anisotropy ◽  
Spiral Arm ◽  
Northern And Southern Hemispheres

AbstractMeasurements of cosmic ray directional properties at about 1015 eV in both northern and southern hemispheres confirm that those particles have a unidirectional anisotropy and are flowing along the direction of our spiral arm from the inner Galactic regions. On the basis of diffusive cosmic ray flow along the Galactic arms, the power required for the Galaxy to maintain this flow is below 1030 W.

scholarly journals Elements in the Cosmos: Origin of the Light Elements

1991 ◽  
Vol 145 ◽  
pp. 3-12
Author(s):  
Hubert Reeves
Keyword(s):  
Cosmic Ray ◽  
Big Bang ◽  
Light Elements ◽  
Big Bang Nucleosynthesis ◽  
Hadron Phase ◽  
Iron Deficient ◽  
The Galaxy ◽  
Galactic Cosmic Ray ◽  
The Big Bang ◽  
Theoretical Developments

In the first part of this paper, a review is given of the situation of the Big Bang nucleosynthesis of the nuclides D, 3He, 4He and 7Li, taking into account the latest experimental data (number of neutrino species, lifetime of the neutron) and theoretical developments (quark-hadron phase transition). In the second part. I review the process of Galactic Cosmic Ray formation of lithium, beryllium and boron throughout the life of the galaxy, taking advantage of recent measurements of Be and Li in iron deficient stars.

Sign in / Sign up

Export Citation Format

Share Document