scholarly journals COSMIC CONNECTIONS: FROM COSMIC RAYS TO GAMMA RAYS, COSMIC BACKGROUNDS AND MAGNETIC FIELDS

2013 ◽  
Vol 28 (02) ◽  
pp. 1340001 ◽  
Author(s):  
ALEXANDER KUSENKO
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Extragalactic Background Light ◽  
Holistic Treatment ◽  
Galactic Sources ◽  
Combined Data

Combined data from gamma-ray telescopes and cosmic-ray detectors have produced some new surprising insights regarding intergalactic and galactic magnetic fields, as well as extragalactic background light. We review some recent advances, including a theory explaining the hard spectra of distant blazars and the measurements of intergalactic magnetic fields based on the spectra of distant sources. Furthermore, we discuss the possible contribution of transient galactic sources, such as past gamma-ray bursts and hypernova explosions in the Milky Way, to the observed flux of ultrahigh-energy cosmic-rays nuclei. The need for a holistic treatment of gamma rays, cosmic rays, and magnetic fields serves as a unifying theme for these seemingly unrelated phenomena.

scholarly journals Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model

2020 ◽  
Vol 500 (1) ◽  
pp. 1087-1094
Author(s):  
Prabir Banik ◽  
Arunava Bhadra ◽  
Abhijit Bhattacharyya
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Scale ◽  
Electromagnetic Spectrum ◽  
Ultrahigh Energy ◽  
Large Area ◽  
Centaurus A

ABSTRACT The nearest active radio galaxy Centaurus (Cen) A is a gamma-ray emitter in GeV–TeV energy scale. The high energy stereoscopic system (HESS) and non-simultaneous Fermi–Large Area Telescope observation indicate an unusual spectral hardening above few GeV energies in the gamma-ray spectrum of Cen A. Very recently the HESS observatory resolved the kilo parsec (kpc)-scale jets in Centaurus A at TeV energies. On the other hand, the Pierre Auger Observatory (PAO) detects a few ultrahigh energy cosmic ray (UHECR) events from Cen-A. The proton blazar inspired model, which considers acceleration of both electrons and hadronic cosmic rays in active galactic nuclei (AGN) jet, can explain the observed coincident high-energy neutrinos and gamma-rays from Ice-cube detected AGN jets. Here, we have employed the proton blazar inspired model to explain the observed GeV–TeV gamma-ray spectrum features including the spectrum hardening at GeV energies along with the PAO observation on cosmic rays from Cen-A. Our findings suggest that the model can explain consistently the observed electromagnetic spectrum in combination with the appropriate number of UHECRs from Cen A.

scholarly journals ULTRA HIGH ENERGY COSMIC RAYS: ORIGIN AND PROPAGATION

2010 ◽  
Vol 25 (18) ◽  
pp. 1467-1481 ◽  
Author(s):  
TODOR STANEV
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Ultrahigh Energy ◽  
High Energy Cosmic Rays ◽  
Astrophysical Objects ◽  
Ultrahigh Energy Cosmic Rays ◽  
The Universe

We introduce the highest energy cosmic rays and briefly review the powerful astrophysical objects where they could be accelerated. We then introduce the interactions of different cosmic ray particles with the photon fields of the Universe and the formation of the cosmic ray spectra observed at Earth. The last topic is the production of secondary gamma rays and neutrinos in the interactions of the ultrahigh energy cosmic rays.

scholarly journals Supernova remnants and the origin of cosmic rays

2013 ◽  
Vol 9 (S296) ◽  
pp. 305-314
Author(s):  
Jacco Vink
Keyword(s):  
Synchrotron Radiation ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Long Time ◽  
Gamma Ray Emission

AbstractSupernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the cosmic ray energy density and spectrum in the Galaxy supernova remnant should use 10% of the explosion energy to accelerate particles, and about 99% of the accelerated particles should be protons and other atomic nuclei.Over the last decade a lot of progress has been made in providing evidence that supernova remnant can accelerate protons to very high energies. The evidence consists of, among others, X-ray synchrotron radiation from narrow regions close to supernova remnant shock fronts, indicating the presence of 10-100 TeV electrons, and providing evidence for amplified magnetic fields, gamma-ray emission from both young and mature supernova remnants. The high magnetic fields indicate that the condition for accelerating protons to >1015 eV are there, whereas the gamma-ray emission from some mature remnants indicate that protons have been accelerated.

Upper limit to the number of galactic sources of ultra-high-energy gamma-rays

1989 ◽  
Vol 8 (2) ◽  
pp. 159-160 ◽  
Author(s):  
D. J. Bird ◽  
R. W. Clay ◽  
P. G. Edwards
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Upper Limits ◽  
Energy Gamma ◽  
Galactic Sources ◽  
Cosmic Ray Flux

AbstractThe extreme isotropy of cosmic ray events allows one to put upper limits on any possible non-isotropic contribution to the flux. In particular, one can investigate any excess of events which may be confined to the galactic plane. Such extra events would be expected from galactic ultra-high-energy (UHE) gamma-ray sources. Under the assumption of an isotropic cosmic ray flux, recent Buckland Park data place a 95% confidence level limit on the total southern hemisphere (declination −15° to −55°) flux of UHE gamma-rays at between 0.6 and 6 equivalent Cygnus X-3 sources, depending on assumptions concerning the gamma-ray spectrum.

scholarly journals NEW RESULTS FROM H.E.S.S. OBSERVATIONS OF GALAXY CLUSTERS

2009 ◽  
Vol 18 (10) ◽  
pp. 1627-1631 ◽  
Author(s):  
◽  
WILFRIED DOMAINKO ◽  
DALIBOR NEDBAL ◽  
JAMES A. HINTON ◽  
OLIVIER MARTINEAU-HUYNH
Keyword(s):  
Cosmic Rays ◽  
Galaxy Clusters ◽  
Gamma Rays ◽  
Large Scale ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Clusters Of Galaxies ◽  
X Ray ◽  
Model Predictions ◽  
The Universe

Clusters of galaxies are believed to contain a significant population of cosmic rays. From the radio and probably hard X-ray bands it is known that clusters are the spatially most extended emitters of non-thermal radiation in the Universe. Due to their content of cosmic rays, galaxy clusters are also potential sources of VHE (> 100 GeV) gamma rays. Recently, the massive, nearby cluster Abell 85 has been observed with the H.E.S.S. experiment in VHE gamma rays with a very deep exposure as part of an ongoing campaign. No significant gamma-ray signal has been found at the position of the cluster. The non-detection of this object with H.E.S.S. constrains the total energy of cosmic rays in this system. For a hard spectral index of the cosmic rays of -2.1 and if the cosmic-ray energy density follows the large scale gas density profile, the limit on the fraction of energy in these non-thermal particles with respect to the total thermal energy of the intra-cluster medium is 8% for this particular cluster. This value is at the lower bounds of model predictions.

scholarly journals Geant4 simulation of the Tunka-Grande experiment

2021 ◽  
Vol 2103 (1) ◽  
pp. 012001
Author(s):  
R Monkhoev ◽  
M Ternovoy ◽  
I Astapov ◽  
P Bezyazeekov ◽  
A Borodin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Gamma Ray ◽  
High Sensitivity ◽  
Cosmic Ray ◽  
Mass Composition ◽  
Future Research ◽  
Simulation Strategy ◽  
Experimental Complex ◽  
Array Imaging

Abstract The Tunka-Grande array is part of a single experimental complex, which also includes the Tunka-133 and TAIGA-HiScORE (High Sensitivity COsmic Rays and gamma Explorer) wide-angle Cherenkov arrays, TAIGA-IACT array (Imaging Atmospheric Cherenkov Telescope) and TAGA-MUON scintillation array. This complex is located in the Tunka Valley (Buryatia Republic, Russia), 50 km from Lake Baikal. It is designed to study the energy spectrum and the mass composition of charged cosmic rays in the energy range 100 TeV - 1000 PeV, to search for diffuse gamma rays above 100 TeV and to study local sources of gamma rays with energies above 30 TeV. This report outlines 3 key points. The first is the description of the Tunka-Grande scintillation array. The second one presents the computer simulation strategy of the Tunka Grande array based on the Geant4 software. The third one is devoted to the prospects for future research in the field of cosmic ray physics and gamma-ray astronomy using simulation results.

scholarly journals An interacting molecular cloud scenario for production of gamma-rays and neutrinos from MAGIC J1835-069, and MAGIC J1837-073

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Prabir Banik ◽  
Arunava Bhadra
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Molecular Cloud ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
Maximum Energy ◽  
Hadronic Interactions ◽  
Extended Sources ◽  
First Time

AbstractRecently the MAGIC telescope observed three TeV gamma-ray extended sources in the galactic plane in the neighborhood of radio SNR G24.7+0.6. Among them, the PWN HESS J1837-069 was detected earlier by the HESS observatory during its first galactic plane survey. The other two sources, MAGIC J1835-069 and MAGIC J1837-073 are detected for the first time at such high energies. Here we shall show that the observed gamma-rays from the SNR G24.7+0.6 and the HESS J1837-069 can be explained in terms of hadronic interactions of the PWN/SNR accelerated cosmic rays with the ambient matter. We shall further demonstrate that the observed gamma-rays from the MAGIC J1837-073 can be interpreted through hadronic interactions of runaway cosmic-rays from PWN HESS J1837-069 with the molecular cloud at the location of MAGIC J1837-073. No such association has been found between MAGIC J1835-069 and SNR G24.7+0.6 or PWN HESS J1837-069. We have examined the maximum energy attainable by cosmic-ray particles in the SNR G24.7+0.6/ PWN HESS J1837-069 and the possibility of their detection with future gamma-ray telescopes. The study of TeV neutrino emissions from the stated sources suggests that the HESS J1837-069 should be detected by IceCube Gen-2 neutrino telescope in a few years of observation.

scholarly journals The Origin and Dynamical Effects of the Magnetic Fields and Cosmic Rays in the Disk of the Galaxy

1970 ◽  
Vol 39 ◽  
pp. 168-183
Author(s):  
E. N. Parker
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Dynamical Behavior ◽  
Cosmic Ray ◽  
Interested Reader ◽  
Written Text ◽  
The Galaxy ◽  
Basic Ideas ◽  
The Magnetic Field

The topic of this presentation is the origin and dynamical behavior of the magnetic field and cosmic-ray gas in the disk of the Galaxy. In the space available I can do no more than mention the ideas that have been developed, with but little explanation and discussion. To make up for this inadequacy I have tried to give a complete list of references in the written text, so that the interested reader can pursue the points in depth (in particular see the review articles Parker, 1968a, 1969a, 1970). My purpose here is twofold, to outline for you the calculations and ideas that have developed thus far, and to indicate the uncertainties that remain. The basic ideas are sound, I think, but, when we come to the details, there are so many theoretical alternatives that need yet to be explored and so much that is not yet made clear by observations.

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