scholarly journals The role of magnetic fields in the formation and propagation of hadronic microquasars jets

2019 ◽  
Vol 23 ◽  
pp. 127
Author(s):  
E.-D. S. Paspaliaris ◽  
T. Smponias ◽  
T. S. Kosmas
Keyword(s):  
Gamma Rays ◽  
Compact Object ◽  
High Energy ◽  
High Energies ◽  
Lorentz Forces ◽  
Neutrino Emissivity ◽  
2D And 3D ◽  
The Magnetic Field ◽  
Very High

In the present work, we examine the role of the magnetic field (MF), which causes a rather pronounced confinement of the jets at microquasars. Due to radial Lorentz forces acting on the jet’s matter towards the jet’s axis, the outgoing flux is collimated along the same axis and vertically to the compact object. Alternatively, a rotating central object may drag the surrounding MF into collimation around the produced jet. In such objects, jet emerges from each side of the accretion disc.These jets operate as cosmic engines, capable of accelerating particles on very high energies (~10^2 TeV) and consist sources of high energy neutrinos and gamma rays. We also examine the role of the MF, which causes to a rather pronounced jet confinement. Our aim is to investigate and model its role on various physical observables of the jet, by simulating the jet’s flow and derive 2D and 3D visualizations and furthermore examine its effect on the neutrino emissivity.

HIGH-ENERGY EMISSION AND ABSORPTION IN CYGNUS X-1

2010 ◽  
Vol 19 (06) ◽  
pp. 763-768
Author(s):  
M. V. DEL VALLE ◽  
M. ORELLANA ◽  
G. E. ROMERO
Keyword(s):  
Soft Power ◽  
Gamma Ray ◽  
Compact Object ◽  
High Energy ◽  
High Mass ◽  
High Energies ◽  
200 Gev ◽  
Very High Energy ◽  
High Energy Emission ◽  
Very High

The high-mass microquasar Cygnus X-1 has been detected during a flaring state at very high energies, E > 200 GeV . The observation was performed by the Atmospheric Cherenkov Telescope MAGIC. It constitutes the first experimental evidence of very-high energy (VHE) emission produced by a Galactic stellar-mass black hole. The observed signal was detected in coincidence with an X–ray flare. The gamma-ray flare occurred when the compact object was located behind the companion star with respect to the line of sight (superior conjunction of the compact object). In this configuration the absorption of VHE photons by annihilation with the stellar photons is expected to be maximum. This suggests that the emission has been originated far above the compact object. The energy spectrum is well fitted by a relatively soft power-law. We present a model for the absorption and the emission of VHE gamma-rays in Cyg X-1. Detailed calculations of the gamma-ray opacity due to pair creation are provided and used to establish constraints on the emitting region. We propose that the high energy flare was the result of the interaction between the jet and a very dense clump from the stellar wind.

scholarly journals Plasma Energetics in Solar Flares

1980 ◽  
Vol 5 ◽  
pp. 343-350 ◽  
Author(s):  
Gerard Van Hoven
Keyword(s):  
Gamma Rays ◽  
Solar Flares ◽  
High Energy ◽  
Physical Mechanisms ◽  
Very High Energy ◽  
Physical Effects ◽  
High Energy Particles ◽  
The Magnetic Field ◽  
Dissipation Processes ◽  
Very High

I want to begin with the observation, which I will try to make clear in the following, that a solar flare comprises an incredibly complex set of phenomena. This is not only true with respect to what is seen and measured in spectacular examples, but also when one considers the constituent parts of simple, even idealized, cases. A series of different physical effects lead, as one illustration, to radiations from the flare-instability site and its surroundings which span the range from meter waves to gamma rays (Svestka 1976, Sturrock 1979).To fit within the context of this discussion, I will concentrate on the high-temperature and quasi-thermal aspects of a flare, and on the basic physical mechanisms connected with the primary energization and dissipation processes. Thus, I will treat the reconnection of the magnetic field, the bulk acceleration of particles, the thermalization and the ultimate radiation of the energy. I will not treat the optical manifestations or, at the other extreme, the acceleration of very high energy particles.

scholarly journals LS I +61 303: MICROQUASAR OR NOT MICROQUASAR?

2008 ◽  
Vol 17 (10) ◽  
pp. 1875-1881
Author(s):  
G. E. ROMERO ◽  
M. ORELLANA ◽  
A. T. OKAZAKI ◽  
S. P. OWOCKI
Keyword(s):  
Neutron Star ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Compact Object ◽  
High Energy ◽  
Very High Energy ◽  
Be Star ◽  
Energy Gamma ◽  
High Energy Emission ◽  
Very High

LS I +61 303 is a puzzling object detected from radio up to very high-energy gamma-rays. Variability has recently been observed in its high-energy emission. The object is a binary system, with a compact object and a Be star as primary. The nature of the secondary and the origin of the gamma-ray emission are not clearly established at present. Recent VLBA radio data have been used to claim that the system is a Be /neutron star colliding wind binary, instead of a microquasar. We review the main views on the nature of LS I +61 303 and present results of 3D SPH simulations that can shed some light on the nature of the system. Our results support an accretion powered source, compatible with a microquasar interpretation.

Deflectometric measurement of large mirrors

2014 ◽  
Vol 3 (3) ◽  
Author(s):  
Evelyn Olesch ◽  
Gerd Häusler ◽  
André Wörnlein ◽  
Friedrich Stinzing ◽  
Christopher van Eldik
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
Spherical Mirror ◽  
Large Space ◽  
Telescope Array ◽  
Spread Function ◽  
Very High Energy ◽  
Energy Gamma ◽  
Concentric Geometry ◽  
Very High

AbstractWe discuss the inspection of large-sized, spherical mirror tiles by ‘Phase Measuring Deflectometry’ (PMD). About 10 000 of such mirror tiles, each satisfying strict requirements regarding the spatial extent of the point-spread-function (PSF), are planned to be installed on the Cherenkov Telescope Array (CTA), a future ground-based instrument to observe the sky in very high energy gamma-rays. Owing to their large radii of curvature of up to 60 m, a direct PSF measurement of these mirrors with concentric geometry requires large space. We present a PMD sensor with a footprint of only 5×2×1.2 m

Very high energy gamma rays from x-ray binary pulsars

1990 ◽  
Vol 16 (12) ◽  
pp. 1773-1803 ◽  
Author(s):  
P M Chadwick ◽  
T J L McComb ◽  
K E Turver
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
X Ray ◽  
Binary Pulsars ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High

RESULTS FROM GALACTIC OBSERVATIONS WITH MAGIC

2010 ◽  
Vol 19 (06) ◽  
pp. 1023-1029
Author(s):  
◽  
JAVIER RICO
Keyword(s):  
Gamma Rays ◽  
Energy Band ◽  
Binary Systems ◽  
High Energy ◽  
Cherenkov Telescope ◽  
La Palma ◽  
Very High Energy ◽  
Energy Gamma ◽  
High Energy Emission ◽  
Very High

MAGIC is a single-dish Cherenkov telescope located on La Palma (Spain), hence with an optimal view on the Northern sky. Sensitive to the 30 GeV–30 TeV energy band, it is nowadays the only ground-based instrument being able to measure high-energy gamma-rays below 100 GeV. With the operation in coincidence with MACIC-II, starting in Fall 2009, the sensitivity will be improved by a factor ~ 2. We review the results obtained by MAGIC on the very-high energy emission from pulsars, binary systems and microquasars.

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