scholarly journals Automatic Prompt Gamma‐Ray Analysis System: Automation of an Existing Large‐Scale Analytical Device

10.5772/64650 ◽  
2016 ◽  
Author(s):  
Takahito Osawa
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Prompt Gamma ◽  
Analysis System ◽  
Analytical Device

scholarly journals The Zone of Avoidance as an X-ray absorber - the role of the galactic foreground modelling Swift XRT spectra

2017 ◽  
Vol 12 (S333) ◽  
pp. 170-171
Author(s):  
I. I. Racz ◽  
Z. Bagoly ◽  
L. V. Tóth ◽  
L. G. Balázs ◽  
I. Horvath ◽  
...  
Keyword(s):  
Column Density ◽  
Large Scale ◽  
Gamma Ray ◽  
Small Scale ◽  
Prompt Gamma ◽  
Gamma Emission ◽  
Essential Information ◽  
X Ray ◽  
Hydrogen Column Density ◽  
Zone Of Avoidance

AbstractGamma-ray bursts (GRBs) are the most powerful explosive events in the Universe. The prompt gamma emission is followed by an X-ray afterglow that is also detected for over nine hundred GRBs by the Swift BAT and XRT detectors. The X-ray afterglow spectrum bears essential information about the burst, and the surrounding interstellar medium (ISM). Since the radiation travels through the line of sight intergalactic medium and the ISM in the Milky Way, the observed emission is influenced by extragalactic and galactic components. The column density of the Galactic foreground ranges several orders of magnitudes, due to both the large scale distribution of ISM and its small scale structures. We examined the effect of local HI column density on the penetrating X-ray emission, as the first step towards a precise modeling of the measured X-ray spectra. We fitted the X-ray spectra using the Xspec software, and checked how the shape of the initially power low spectrum changes with varying input Galactic HI column density. The total absorbing HI column is a sum of the intrinsic and Galactic component. We also investigated the model results for the intrinsic component varying the Galactic foreground. We found that such variations may alter the intrinsic hydrogen column density up to twenty-five percent. We will briefly discuss its consequences.

scholarly journals RIKEN Accelerator-driven compact neutron systems

2020 ◽  
Vol 231 ◽  
pp. 01009 ◽  
Author(s):  
Yoshie Otake
Keyword(s):  
Fast Neutron ◽  
Evaluation System ◽  
Large Scale ◽  
Gamma Ray ◽  
Nuclear Data ◽  
Low Energy ◽  
Proton Accelerator ◽  
Prompt Gamma ◽  
Neutron Diffractometer ◽  
Transmission Imaging

RIKEN Accelerator-driven compact neutron source, RANS, has been operational since 2013. There are two major goals of RANS research and development. One is to establish a new compact low energy neutron non-destructive evaluation system on-site of floor-standing type for industrial use. Another goal is to invent a novel transportable compact neutron system for the preventive maintenance of large scale construction such as a bridge. The low energy transmission imaging, neutron diffractometer, small angle scattering instruments, fast neutron transmission imaging, fast neutron back scattering imaging, neutron induced prompt gamma-ray analysis and neutron activation analysis are available with RANS. To solve the lack of nuclear data to develop compact neutron sources, we have created new function which gives neutron spectrum from the 9Be +p reaction with protons of energy below 12 MeV. For further compact neutron system, RANS-II is now ready to generate neutrons in the RANS experimental hall with individual shielding system. The novel proton accelerator tube and 500 MHz solid state high-frequency amplifier for RANS-III, of a transportable neutron system, are now ready to be developed in RIKEN.

scholarly journals Modeling Gamma-Ray SEDs and Angular Extensions of Extreme TeV Blazars from Intergalactic Proton-Initiated Cascades in Contemporary Astrophysical EGMF Models

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 220
Author(s):  
Emil Khalikov
Keyword(s):  
Gamma Rays ◽  
Large Scale ◽  
Gamma Ray ◽  
High Energy ◽  
Cascade Model ◽  
Point Sources ◽  
Spectral Energy ◽  
Observation Data ◽  
Cherenkov Telescopes ◽  
The Universe

The intrinsic spectra of some distant blazars known as “extreme TeV blazars” have shown a hint at an anomalous hardening in the TeV energy region. Several extragalactic propagation models have been proposed to explain this possible excess transparency of the Universe to gamma-rays starting from a model which assumes the existence of so-called axion-like particles (ALPs) and the new process of gamma-ALP oscillations. Alternative models suppose that some of the observable gamma-rays are produced in the intergalactic cascades. This work focuses on investigating the spectral and angular features of one of the cascade models, the Intergalactic Hadronic Cascade Model (IHCM) in the contemporary astrophysical models of Extragalactic Magnetic Field (EGMF). For IHCM, EGMF largely determines the deflection of primary cosmic rays and electrons of intergalactic cascades and, thus, is of vital importance. Contemporary Hackstein models are considered in this paper and compared to the model of Dolag. The models assumed are based on simulations of the local part of large-scale structure of the Universe and differ in the assumptions for the seed field. This work provides spectral energy distributions (SEDs) and angular extensions of two extreme TeV blazars, 1ES 0229+200 and 1ES 0414+009. It is demonstrated that observable SEDs inside a typical point spread function of imaging atmospheric Cherenkov telescopes (IACTs) for IHCM would exhibit a characteristic high-energy attenuation compared to the ones obtained in hadronic models that do not consider EGMF, which makes it possible to distinguish among these models. At the same time, the spectra for IHCM models would have longer high energy tails than some available spectra for the ALP models and the universal spectra for the Electromagnetic Cascade Model (ECM). The analysis of the IHCM observable angular extensions shows that the sources would likely be identified by most IACTs not as point sources but rather as extended ones. These spectra could later be compared with future observation data of such instruments as Cherenkov Telescope Array (CTA) and LHAASO.

scholarly journals Understanding the origin of the positron annihilation line and the physics of supernova explosions

2021 ◽  
Author(s):  
F. Frontera ◽  
E. Virgilli ◽  
C. Guidorzi ◽  
P. Rosati ◽  
R. Diehl ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Large Scale ◽  
Gamma Ray ◽  
Nuclear Astrophysics ◽  
High Energy ◽  
Radioactive Isotopes ◽  
Fusion Reactions ◽  
Dark Matter Annihilation ◽  
Annihilation Line ◽  
Supernova Explosions

AbstractNuclear astrophysics, and particularly nuclear emission line diagnostics from a variety of cosmic sites, has remained one of the least developed fields in experimental astronomy, despite its central role in addressing a number of outstanding questions in modern astrophysics. Radioactive isotopes are co-produced with stable isotopes in the fusion reactions of nucleosynthesis in supernova explosions and other violent events, such as neutron star mergers. The origin of the 511 keV positron annihilation line observed in the direction of the Galactic Center is a 50-year-long mystery. In fact, we still do not understand whether its diffuse large-scale emission is entirely due to a population of discrete sources, which are unresolved with current poor angular resolution instruments at these energies, or whether dark matter annihilation could contribute to it. From the results obtained in the pioneering decades of this experimentally-challenging window, it has become clear that some of the most pressing issues in high-energy astrophysics and astro-particle physics would greatly benefit from significant progress in the observational capabilities in the keV-to-MeV energy band. Current instrumentation is in fact not sensitive enough to detect radioactive and annihilation lines from a wide variety of phenomena in our and nearby galaxies, let alone study the spatial distribution of their emission. In this White Paper (WP), we discuss how unprecedented studies in this field will become possible with a new low-energy gamma-ray space experiment, called ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics), which combines new imaging, spectroscopic and polarization capabilities. In a separate WP (Guidorzi et al. 39), we discuss how the same mission concept will enable new groundbreaking studies of the physics of Gamma–Ray Bursts and other high-energy transient phenomena over the next decades.

scholarly journals Localization of inclusions in multiple prompt gamma ray analysis: a feasibility study

2013 ◽  
Vol 470 ◽  
pp. 012001 ◽  
Author(s):  
A Miceli ◽  
G Festa ◽  
R Senesi ◽  
G Gorini ◽  
C Andreani
Keyword(s):  
Feasibility Study ◽  
Gamma Ray ◽  
Prompt Gamma

PO-1728: Development of a new prompt gamma ray detection system for full 3D proton range verification

2020 ◽  
Vol 152 ◽  
pp. S957-S958
Author(s):  
P. Costanza ◽  
R.I. Mackay ◽  
K.J. Kirkby ◽  
M.J. Taylor
Keyword(s):  
Gamma Ray ◽  
Detection System ◽  
Prompt Gamma ◽  
Range Verification

scholarly journals Optical Afterglows as Probes for the Central Engine and Fireball of Gamma-Ray Bursts

2012 ◽  
Vol 8 (S290) ◽  
pp. 263-264
Author(s):  
Liang Li ◽  
En-Wei Liang ◽  
He Gao ◽  
Bing Zhang
Keyword(s):  
Statistical Analysis ◽  
Gamma Rays ◽  
Density Profile ◽  
Gamma Ray ◽  
Ambient Medium ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
Medium Density ◽  
Central Engine ◽  
Prompt Emission

AbstractWell-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are compiled from literature. We identify possible emission components based on our empirical fits and present statistical analysis for these components. We find that the flares are related to prompt emission, suggesting that they could have the same origin in different episodes. The shallow decay segment is not correlated with prompt gamma-rays. It likely signals a long-lasting injected wind from GRB central engines. Early after onset peak is closely related with prompt emission. The ambient medium density profile is likely n ∝ r−1. No correlation between the late re-brightening bump and prompt gamma-rays or the onset bump is found. They may be from another jet component.

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