scholarly journals Neutron and gamma-ray fluxes measured by SciCRT prototype at the top of Sierra Negra volcano, Mexico

2019 ◽  
Vol 65 (5 Sept-Oct) ◽  
pp. 545
Author(s):  
E. Ortiz ◽  
J. F. Valdés-Galicia ◽  
A. Hurtado ◽  
R. García ◽  
M. Anzorena ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Forbush Decrease ◽  
Cosmic Ray ◽  
Parameter Tuning ◽  
Incident Radiation ◽  
Maximum Energy ◽  
Operation Parameter ◽  
Sierra Negra Volcano ◽  
Sierra Negra

The mini-SciCR is a cosmic ray detector, it is made of scintillator bars with a total volume of 20 x 20 x 20.8 $cm^{3}$. The array of scintillator bars act both as a target and as a tracker of the incident radiation. In this paper we describe the method developed with the help of a Monte Carlo simulation to distiguish the neutron signals from gamma ray signals, it is based on the different maximum energy deposited at a scintillator bar by neutrons and gamma rays. To distiguish the neutral emission signals (neutrons and gamma rays) from charged particles signals, we implemented via software a system of anti-coincidence between edge bars and internal bars of the detector. We also report the flux of neutrons and gamma rays measured by the mini-SciCR at the top of the Sierra Negra volcano at 4,600 m.a.s.l., in Eastern Mexico. The mini-SciCR was operating from October 2010 to July 2012. We also present the Forbush decrease registered by the mini-SciCR on march, 2012. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope installed in the same place, which is in the process of operation parameter tuning and calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope.

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 Observation of cosmic ray hadrons at the top of the Sierra Negra volcano in Mexico with the SciCRT prototype

2016 ◽  
Vol 58 (10) ◽  
pp. 2018-2025
Author(s):  
E. Ortiz ◽  
J.F. Valdés-Galicia ◽  
Y. Matsubara ◽  
Y. Nagai ◽  
A. Hurtado ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Sierra Negra Volcano ◽  
Sierra Negra

scholarly journals Secondary-electron radiation accompanying hadronic GeV–TeV gamma-rays from supernova remnants

2020 ◽  
Vol 492 (3) ◽  
pp. 4246-4253 ◽  
Author(s):  
Yan Huang ◽  
Zhuo Li ◽  
Wei Wang ◽  
Xiaohong Zhao
Keyword(s):  
Synchrotron Radiation ◽  
Gamma Rays ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Far Infrared ◽  
Hadronic Interactions ◽  
Electrons And Positrons ◽  
Tev Gamma Rays ◽  
The Magnetic Field

ABSTRACT The synchrotron radiation from secondary electrons and positrons (SEPs) generated by hadronic interactions in the shock of supernova remnant (SNR) could be a distinct evidence of cosmic ray (CR) production in SNR shocks. Here, we provide a method where the observed gamma-ray flux from SNRs, created by pion decays, is directly used to derive the SEP distribution and hence the synchrotron spectrum. We apply the method to three gamma-ray bright SNRs. In the young SNR RX J1713.7−3946, if the observed GeV−TeV gamma-rays are of hadronic origin and the magnetic field in the SNR shock is B ≳ 0.5 mG, the SEPs may produce a spectral bump at 10−5–10−2 eV, exceeding the predicted synchrotron component of the leptonic model, and a soft spectral tail at ≳100 keV, distinct from the hard spectral slope in the leptonic model. In the middle-aged SNRs IC443 and W44, if the observed gamma-rays are of hadronic origin, the SEP synchrotron radiation with B ∼ 400–500 μG can well account for the observed radio flux and spectral slopes, supporting the hadronic origin of gamma-rays. Future microwave to far-infrared and hard X-ray (>100keV) observations are encouraged to constraining the SEP radiation and the gamma-ray origin in SNRs.

scholarly journals What do Gamma Rays tell us about the ISM?: New Insight from the Compton Observatory

1996 ◽  
Vol 169 ◽  
pp. 437-446 ◽  
Author(s):  
Hans Bloemen
Keyword(s):  
Interstellar Medium ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Line Emission ◽  
Cosmic Ray ◽  
Gamma Ray Astronomy ◽  
Early Results ◽  
The Galaxy ◽  
Γ Ray ◽  
Insight Into

Gamma-ray astronomy has become a rich field of research and matured significantly since the launch of NASA's Compton Gamma Ray Observatory in April 1991. Studies of the diffuse γ-ray emission of the Galaxy can now be performed in far more detail and extended into the MeV regime, including both continuum and line emission. These studies provide unique insight into various aspects of the interstellar medium, in particular of the cosmic-ray component. This paper gives a brief review on the diffuse Galactic γ-ray emission and summarizes early results and prospects from the Compton Observatory.

scholarly journals Interaction between molecular clouds and MeV–TeV cosmic-ray protons escaped from supernova remnants

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Ken Makino ◽  
Yutaka Fujita ◽  
Kumiko K Nobukawa ◽  
Hironori Matsumoto ◽  
Yutaka Ohira
Keyword(s):  
Gamma Rays ◽  
Molecular Clouds ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Iron Line ◽  
X Ray ◽  
Line Intensities ◽  
Neutral Gas ◽  
Additional Support

Abstract Recent discovery of the X-ray neutral iron line (Fe  i Kα at 6.40 keV) around several supernova remnants (SNRs) show that MeV cosmic-ray (CR) protons are distributed around the SNRs and are interacting with neutral gas there. We propose that these MeV CRs are the ones that have been accelerated at the SNRs together with GeV–TeV CRs. In our analytical model, the MeV CRs are still confined in the SNR when the SNR collides with molecular clouds. After the collision, the MeV CRs leak into the clouds and produce the neutral iron line emissions. On the other hand, GeV–TeV CRs had already escaped from the SNRs and emitted gamma-rays through interaction with molecular clouds surrounding the SNRs. We apply this model to the SNRs W 28 and W 44 and show that it can reproduce the observations of the iron line intensities and the gamma-ray spectra. This could be additional support of the hadronic scenario for the gamma-ray emissions from these SNRs.

scholarly journals Linking supernovae and supernova remnants. Time-dependent injection in SN1987A and gamma-ray spectrum of IC443

2017 ◽  
Vol 12 (S331) ◽  
pp. 268-273
Author(s):  
O. Petruk ◽  
S. Orlando ◽  
M. Miceli
Keyword(s):  
Gamma Rays ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Supernova Explosion ◽  
Cosmic Ray ◽  
Proton Spectrum ◽  
Stationary Equation ◽  
Particle Injection ◽  
Particle Momentum ◽  
Number Of Particles

AbstractAcceleration times of particles responsible for the gamma-rays in supernova remnants (SNRs) are comparable with SNR age. If the number of particles starting acceleration was varying during early times after the supernova explosion then this variation should be reflected in the shape of the gamma-ray spectrum. In order to analyse this effect, we consider the time variation of the radio spectral index in SN1987A and solution of the non-stationary equation for particle acceleration. We reconstruct evolution of the particle injection in SN1987A, apply it to derive the particle momentum distribution in IC443 and model its gamma-ray spectrum. We show that: i) observed break in the proton spectrum around 50 GeV in IC443 is a consequence of the variation of the cosmic ray injection; ii) shape of the hadronic gamma-ray spectrum in SNRs critically depends on the temporal variation of the cosmic ray injection in the immediate post explosion phases.

scholarly journals British plans for astronomy in Antarctica

1992 ◽  
Vol 9 ◽  
pp. 599-599
Author(s):  
R D Davies ◽  
J M Hough
Keyword(s):  
Gamma Rays ◽  
Small Area ◽  
Gamma Ray ◽  
Angular Resolution ◽  
State Of The Art ◽  
Austral Summer ◽  
Cosmic Ray ◽  
South Pole ◽  
Gamma Ray Astronomy ◽  
Air Shower

The South Pole air shower experiment (SPASE), a joint Bartol Research Institute and Leeds University project, has been operational since the austral summer of 1987/88. It is a cosmic ray telescope searching for cosmic gamma rays at energies up to 1000 TeV. Although it has a relatively small area (6800 m2), it is situated at an altitude of 2800 m and has a 24 hour coverage, making it very competitive. The angular resolution of 0.°8 at 200 TeV is state-of-the-art in gamma ray astronomy. The astronomical programme includes searches for gamma ray sources, searches for anisotropy in the cosmic ray sky and measuring the energy spectrum over the range 1014-1016 eV.

scholarly journals Recent Results on the Search for 1011 eV Gamma Rays from the Crab Nebula

1971 ◽  
Vol 46 ◽  
pp. 65-67
Author(s):  
G. G. Fazio ◽  
H. F. Helmken ◽  
G. H. Rieke ◽  
T. C. Weekes
Keyword(s):  
Magnetic Field ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Crab Nebula ◽  
Cosmic Ray ◽  
Air Showers ◽  
Upper Limit ◽  
The Crab Nebula ◽  
Cerenkov Light ◽  
Significant Flux

The detection of Čerenkov light emitted by cosmic-ray air showers was used to search for cosmic gamma rays from the Crab Nebula. By use of the 10-m optical reflector at Mt. Hopkins, Arizona, the Crab Nebula was observed during the winter of 1969–1970 for approximately 112 hours, which was a significant increase in exposure time over previous experiments. Above a gamma-ray energy of 2.2 × 1011 eV, no significant flux was detected, resulting in an upper limit to the flux of 8.1 × 10-11 photon/cm2 sec. In the synchrotron-Compton-scattering model of gamma-ray production in the Crab Nebula, this limit on the flux indicates the average magnetic field in the nebula must be greater than 3 × 10-4 G.

scholarly journals Highlights from HAWC

2019 ◽  
Vol 208 ◽  
pp. 14001
Author(s):  
H. León Vargas
Keyword(s):  
Energy Range ◽  
High Altitude ◽  
High Precision ◽  
Gamma Rays ◽  
Large Data ◽  
Cosmic Ray ◽  
Air Showers ◽  
Data Set ◽  
Sierra Negra Volcano ◽  
Selection Of

The HAWC (High Altitude Water Cherenkov) observatory, located on the slopes of the Sierra Negra volcano in the state of Puebla, Mexico, was designed with the goal of detecting gamma-rays in the Teraelectron- volt energy range. However, most of the air showers that are detected with the observatory, with a rate of ≈ 27 kHz, are of hadronic origin. This makes that, after three years of operations, HAWC has accumulated a very large data set that allows to perform cosmic-ray analysis of high precision. The details of the observatory operation, as well as a selection of recent results in cosmic-ray physics are discussed in this work.

Diffuse Gamma Rays of Galactic and Extragalactic Origin: Preliminary Results from EGRET

1996 ◽  
Vol 168 ◽  
pp. 279-288
Author(s):  
P. Sreekumar ◽  
D.A. Kniffen
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Emission Model ◽  
Diffuse Emission ◽  
Interstellar Gas ◽  
Cosmic Ray Interactions ◽  
Galactic Model ◽  
Energy Gamma

The all-sky survey in high energy gamma rays (E>30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory provides for the first time an opportunity to examine in detail diffuse gamma-ray emission of extra-galactic origin. The observed diffuse emission at high galactic latitudes is generally assumed to have a galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation, in addition to an isotropic component presumably of extragalactic origin. The galactic component can be estimated from a model of the interstellar medium and cosmic-ray distribution. Since the derived extragalactic spectrum depends very much on the success of our galactic model, the consistency of the galactic diffuse emission model is examined both spectrally and spatially with existing EGRET observations. In conjunction with this model, EGRET observations of the high latitude emission are used to examine the flux and spectrum of the residual extragalactic emission. This residual emission could be either truly diffuse in origin or could arise from accumulated emission from unresolved sources particularly in the light of EGRET observations showing the presence of numerous gamma-ray bright active galactic nuclei.

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