scholarly journals Synchrotron mechanism of X-ray and gamma-ray emissions in lightning and spark discharges

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. I. Petrov
Keyword(s):  
Power Spectrum ◽  
Discharge Channel ◽  
Gamma Ray ◽  
Lightning Discharge ◽  
High Energy ◽  
Relativistic Velocity ◽  
Polarization Current ◽  
Radiation Mechanism ◽  
X Ray ◽  
Long Tails

AbstractX-ray and γ-ray emissions observed in lightning and long sparks are usually connected with the bremsstrahlung of high-energy runaway electrons. Here, an alternative physical mechanism for producing X-ray and gamma-ray emissions caused by the polarization current and associated electromagnetic field moving with relativistic velocity along a curved discharge channel has been proposed. The existence of fast electromagnetic surface waves propagating along the lightning discharge channel at a speed close to the speed of light in vacuum is shown. The possibility of the production of microwave, X-ray and gamma-ray emissions by a polarization current pulse moving along a curved path via synchrotron radiation mechanism is pointed out. The existence of long tails in the power spectrum is shown, which explains observations of photon energies in the range of 10–100 MeV in the terrestrial gamma-ray flashes, as well as measured power spectrum of laboratory spark discharge.

scholarly journals Synchrotron mechanism of X-ray and gamma-ray emissions in lightning and spark discharges

2021 ◽  
Author(s):  
Nikolai Petrov
Keyword(s):  
Power Spectrum ◽  
Discharge Channel ◽  
Gamma Ray ◽  
Lightning Discharge ◽  
High Energy ◽  
Relativistic Velocity ◽  
Polarization Current ◽  
Radiation Mechanism ◽  
X Ray ◽  
Long Tails

Abstract X-ray and γ-ray emissions observed in lightning and long sparks are usually connected with the bremsstrahlung of high-energy runaway electrons. Here, an alternative physical mechanism for producing X-ray and gamma-ray emissions caused by the polarization current and associated electromagnetic field moving with relativistic velocity along a curved discharge channel has been proposed. The existence of fast electromagnetic surface waves propagating along the lightning discharge channel at a speed close to the speed of light in vacuum is shown. The possibility of the production of microwave, X-ray and gamma-ray emissions by a polarization current pulse moving along a curved path via synchrotron radiation mechanism is pointed out. The existence of long tails in the power spectrum is shown, which explains observations of photon energies in the range of 10-100 MeV in the TGF, as well as measured power spectrum of laboratory spark discharge.

scholarly journals Gamma-Ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Yoshiyuki Inoue ◽  
Dmitry Khangulyan ◽  
Akihiro Doi
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Thermal Activity ◽  
X Ray ◽  
Cascade Models ◽  
Coronal Activity ◽  
Ngc 1068 ◽  
High Energy Particles

To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the existence of weak non-thermal coronal activity. In addition, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10 yr survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current observational understanding of AGN coronae and describes how AGN coronae generate high-energy particles. We also provide ways to test the AGN corona model with radio, X-ray, MeV gamma ray, and high-energy neutrino observations.

scholarly journals Fermi-LAT and WMAP observations of the supernova remnant Puppis A

2013 ◽  
Vol 9 (S296) ◽  
pp. 295-299
Author(s):  
Marie-Hélène Grondin ◽  
John W. Hewitt ◽  
Marianne Lemoine-Goumard ◽  
Thierry Reposeur ◽  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
High Energy ◽  
Radio Spectrum ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Large Area ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Γ Ray

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

scholarly journals Imaging in Hard X-ray Astronomy

2003 ◽  
Vol 214 ◽  
pp. 70-83 ◽  
Author(s):  
T. P. Li
Keyword(s):  
Gamma Ray ◽  
Signal To Noise Ratio ◽  
High Energy ◽  
High Signal ◽  
Wide Field ◽  
X Rays ◽  
X Ray ◽  
Energy Gamma ◽  
High Resolution Images ◽  
Energy Processes

The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray bands, currently imaging in the hard X-ray band is mainly achieved through various modulation techniques. A new inversion technique, the direct demodulation method, has been developed since early 90s. with this technique, wide field and high resolution images can be derived from scanning data of a simple collimated detector. The feasibility of this technique has been confirmed by experiment, balloon-borne observation and analyzing simulated and real astronomical data. Based the development of methodology and instrumentation, a high energy astrophysics mission – Hard X-ray Modulation Telescope (HXMT) has been proposed and selected in China for a four-year Phase-A study. The main scientific objectives are a full-sky hard X-ray (20–200 keV) imaging survey and high signal-to-noise ratio timing studies of high energy sources.

scholarly journals Gamma-Ray Pulsar Emission Models

1996 ◽  
Vol 160 ◽  
pp. 315-322 ◽  
Author(s):  
Alice K. Harding
Keyword(s):  
Spectral Index ◽  
Gamma Ray ◽  
High Energy ◽  
Pulsar Emission ◽  
High Energy Radiation ◽  
X Ray ◽  
Gamma Ray Detectors ◽  
Emerging Patterns ◽  
Increased Sensitivity ◽  
Emission Models

AbstractWith the increased sensitivity of gamma-ray detectors on the Compton Gamma-Ray Observatory (CGRO) the number of presently known gamma-ray pulsars has grown. The new detections are beginning to provide clues to the origin of the high-energy radiation in the form of emerging patterns and correlations among observed quantities such as gamma-ray efficiency and spectral index vs. age. But there are still many questions about the location of the emission and its relation to the radio, optical and X-ray pulses. This paper will review models for gamma-ray emission from pulsars and will examine how well the detailed predictions of these models account for the existing observations.

scholarly journals Time-Domain Astronomy with Swift, Fermi and Lobster

2011 ◽  
Vol 7 (S285) ◽  
pp. 41-46 ◽  
Author(s):  
Neil Gehrels ◽  
Scott D. Barthelmy ◽  
John K. Cannizzo
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Tidal Disruption ◽  
X Ray ◽  
Order Of Magnitude ◽  
New Type ◽  
The Crab Nebula ◽  
High Energy Emission ◽  
Higher Sensitivity

AbstractThe dynamic transient gamma-ray sky is revealing many interesting results, largely due to findings by Fermi and Swift. The list includes new twists on gamma-ray bursts (GRBs), a GeV flare from a symbiotic star, GeV flares from the Crab Nebula, high-energy emission from novae and supernovae, and, within the last year, a new type of object discovered by Swift—a jetted tidal disruption event. In this review we present highlights of these exciting discoveries. A new mission concept called Lobster is also described; it would monitor the X-ray sky at order-of-magnitude higher sensitivity than current missions can.

scholarly journals INVESTIGATION OF DENSE GAS TOWARDS RELATIVISTIC OUTFLOW SOURCES

2014 ◽  
Vol 28 ◽  
pp. 1460198
Author(s):  
J. HAWKES ◽  
G. ROWELL ◽  
B. DAWSON ◽  
F. AHARONIAN ◽  
M. BURTON ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Line Emission ◽  
High Energy ◽  
Dense Gas ◽  
Relativistic Jets ◽  
Hii Region ◽  
X Ray ◽  
Stellar Cluster ◽  
Radio Recombination Line ◽  
Low Mass

We probe the interstellar medium towards the objects Circinus X-1, a low-mass X-ray binary with relativistic jets; and the highly energetic Westerlund 2 stellar cluster, which is located towards TeV gamma-ray emission and interesting arc- and jet-like features seen in Nanten 12CO data. We have mapped both regions with the Mopra radio telescope, in 7 mm and 12 mm wavebands, looking for evidence of disrupted/dense gas caused by the interaction between high energy outflows and the ISM. Towards Westerlund 2, peaks in CS(J=1-0) emission indicate high density gas towards the middle of the arc and the endpoint of the jet; and radio recombination line emission is seen overlapping the coincident HII region RCW49. Towards Circinus X-1, 12CO(J = 1-0) Nanten data reveals three molecular clouds that lie in the region of Cir X-1. Gas parameters for each cloud are presented here.

Study on Thallium Bromide Radioactive Detector

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
He Li-xia ◽  
Hao Xiao-yong ◽  
He Gao-kui
Keyword(s):  
High Energy Physics ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Nuclear Material ◽  
High Energy ◽  
Device Fabrication ◽  
Signal Acquisition ◽  
X Ray ◽  
Thallium Bromide ◽  
And Performance

Thallium bromide (TlBr) is a compound semiconductor material, which can be used for X-ray and gamma-ray detectors and can be used at room temperature. It has excellent physical properties, high atomic number and density, wide bandgap (B = 2.68 eV), and low ionization energy. Compared with other X-ray and gamma-ray detection materials, TlBr devices have high detection efficiency and excellent energy resolution performance. So TlBr is suitable for housing in small tubes or shells, and it can be widely used in nuclear material measurement, safeguards verification, national security, space high-energy physics research, and other fields. Based on the fabrication of TlBr prototype detector, this paper focuses on the device fabrication and signal acquisition technology. Gamma-ray spectrum measurements and performance tests are carried out with AM-241 radioactive source. The results show that the special photoelectric peak of 59.5 keV is clearly visible, and the optimal resolution is 4.15 keV (7%).

scholarly journals Simulations of Gamma-Ray Emission from Magnetized Microquasar Jets

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Odysseas Kosmas ◽  
Theodoros Smponias
Keyword(s):  
Gamma Ray ◽  
Initial Conditions ◽  
Stellar System ◽  
Compact Object ◽  
High Energy ◽  
Radiative Properties ◽  
Flow Density ◽  
Hadronic Jets ◽  
X Ray ◽  
Jet Plasma

In this work, we simulate γ-rays created in the hadronic jets of the compact object in binary stellar systems known as microquasars. We utilize as the main computational tool the 3D relativistic magnetohydrodynamical code PLUTO combined with in-house derived codes. Our simulated experiments refer to the SS433 X-ray binary, a stellar system in which hadronic jets have been observed. We examine two new model configurations that employ hadron-based emission mechanisms. The simulations aim to explore the dependence of the γ-ray emissions on the dynamical as well as the radiative properties of the jet (hydrodynamic parameters of the mass-flow density, gas-pressure, temperature of the ejected matter, high energy proton population inside the jet plasma, etc.). The results of the two new scenarios of initial conditions for the microquasar stellar system studied are compared to those of previously considered scenarios.

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