scholarly journals Constraining the contribution of Gamma-Ray Bursts to the high-energy diffuse neutrino flux with 10 yr of ANTARES data

2020 ◽  
Vol 500 (4) ◽  
pp. 5614-5628
Author(s):  
A Albert ◽  
M André ◽  
M Anghinolfi ◽  
G Anton ◽  
M Ardid ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Neutrino Flux ◽  
Radial Distance ◽  
Optimization Procedure ◽  
Lorentz Factor ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Model Parameters ◽  
The Impact ◽  
Astrophysical Neutrino

ABSTRACT Addressing the origin of the astrophysical neutrino flux observed by IceCube is of paramount importance. Gamma-Ray Bursts (GRBs) are among the few astrophysical sources capable of achieving the required energy to contribute to such neutrino flux through pγ interactions. In this work, ANTARES data have been used to search for upward going muon neutrinos in spatial and temporal coincidence with 784 GRBs occurred from 2007 to 2017. For each GRB, the expected neutrino flux has been calculated in the framework of the internal shock model and the impact of the lack of knowledge on the majority of source redshifts and on other intrinsic parameters of the emission mechanism has been quantified. It is found that the model parameters that set the radial distance where shock collisions occur have the largest impact on neutrino flux expectations. In particular, the bulk Lorentz factor of the source ejecta and the minimum variability time-scale are found to contribute significantly to the GRB-neutrino flux uncertainty. For the selected sources, ANTARES data have been analysed by maximizing the discovery probability of the stacking sample through an extended maximum-likelihood strategy. Since no neutrino event passed the quality cuts set by the optimization procedure, 90 per cent confidence level upper limits (with their uncertainty) on the total expected diffuse neutrino flux have been derived, according to the model. The GRB contribution to the observed diffuse astrophysical neutrino flux around 100 TeV is constrained to be less than 10 per cent.

scholarly journals e±-rich GRB Fireball and Infrared Flashes

2003 ◽  
Vol 214 ◽  
pp. 331-332
Author(s):  
Zhuo Li ◽  
Z. G. Dai ◽  
T. Lu
Keyword(s):  
Gamma Ray ◽  
Lorentz Factor ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Rapid Response ◽  
Model Parameters ◽  
Wide Range ◽  
Very High Energy ◽  
Very High

Gamma-ray bursts (GRBs) are believed to originate from ultra-relativistic fireballs, with initial Lorentz factor η ∼ 102 − 103. However very high energy photons may still suffer from γγ interaction. We show here that in a wide range of model parameters, the resulting pairs may dominate electrons associated with the fireball baryons. This may provide an explanation for the rarity of prompt optical detections. A rapid response to the GRB trigger at the IR band would detect such a strong flash.

ON THE PRODUCTION OF HIGH-ENERGY NEUTRINOS IN GAMMA-RAY BURSTS

2014 ◽  
Vol 28 ◽  
pp. 1460207
Author(s):  
MATIAS M. REYNOSO
Keyword(s):  
Energy Loss ◽  
Gamma Ray ◽  
Neutrino Flux ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Proton Proton ◽  
Preliminary Results ◽  
Acceleration Zone ◽  
High Energy Neutrinos

We present preliminary results of a model with two zones in order to study the production of high energy neutrinos at the prompt phase of gamma-ray bursts (GRB). We consider an acceleration zone, where protons and electrons are injected and accelerated, being subject to synchrotron, proton-proton, and proton-gamma cooling. We also assume that they can escape from this zone at a certain rate. The produced pions and the decaying muons are also subject to energy loss and gain processes within the acceleration zone, and the escaping ones are re-injected in a second zone where acceleration no longer operates. We compute the neutrino output expected from both of these zones using typical GRB parameters, and integrate in the redshift to obtain a diffuse neutrino flux which can be different from the expected within one-zone models.

scholarly journals GAMMA-RAY EMISSION OF RELATIVISTIC JETS AS A SUPERCRITICAL PROCESS

2008 ◽  
Vol 17 (09) ◽  
pp. 1611-1617 ◽  
Author(s):  
B. E. STERN ◽  
J. POUTANEN
Keyword(s):  
Gamma Ray ◽  
Galactic Nuclei ◽  
Lorentz Factor ◽  
High Energy ◽  
Relativistic Fluids ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Astrophysical Objects ◽  
Particle Propagation ◽  
The Impact

Supercriticality of the same kind as that in a nuclear pile can take place in high-energy astrophysical objects producing a number of impressive effects. For example, it could cause an explosive release of the energy of a cloud of ultrarelativistic protons into radiation. More certainly, supercriticality should be responsible for energy dissipation of very energetic relativistic fluids such as ultrarelativistic shocks in gamma-ray bursts and jets in active galactic nuclei (AGNs). In this case, the photon breeding process operates. It is a kind of converter mechanism with the high-energy photons and e+e- pairs converting into each other via pair production and inverse Compton scattering. Under certain conditions, which should be satisfied in powerful AGNs, the photon breeding mechanism becomes supercritical: the high-energy photons breed exponentially until their feedback on the fluid changes its velocity pattern. Then the system comes to a self-adjusting near-critical steady state. Monte-Carlo simulations with detailed treatment of particle propagation and interactions demonstrate that a jet with a Lorentz factor Γ ≈ 20 can radiate away up to a half of its total energy, and for Γ = 40 the radiation efficiency can be up to 80 per cent. Outer layers of the jet decelerate down to a moderate Lorentz factor 2–4, while the spine of the jet has a final Lorentz factor in the range 10–20 independent of the initial Γ. Such sharp deceleration under the impact of radiation must cause a number of interesting phenomena such as formation of internal shocks and an early generation of turbulence.

scholarly journals Doppler Boosting Effect on the Jet Radiation of Gamma-Ray Bursts and Active Galactic Nuclei

2016 ◽  
Vol 12 (S324) ◽  
pp. 82-84
Author(s):  
Xiao-Li Huang ◽  
Hai-Ming Zhang ◽  
Shu-Qing Zhong ◽  
En-Wei Liang
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Lorentz Factor ◽  
High Energy ◽  
Mass Scale ◽  
Gamma Ray Bursts ◽  
Radiation Physics ◽  
Physical Laws ◽  
Bl Lacs

AbstractHigh energy photon radiations of gamma-ray bursts (GRBs) and active galactic nuclei (AGNs) are dominated by their jet radiations. It was suggested that relativistic jets powered by different mass-scale black holes may share the same physical laws. A tight relation among the peak luminosity, the peak photon energy in the νfν spectrum, and the initial Lorentz factor is found for GRBs. With samples of GeV-TeV BL Lacs, FSRQs, and NLS1 galaxies, we show that these sources do not follow this relation. This may be attributed to the jet geometry and continuous/episodic jet as well as radiation physics for different kinds of sources.

scholarly journals Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert

Science ◽  
2018 ◽  
Vol 361 (6398) ◽  
pp. 147-151 ◽  
Author(s):  
◽  
Mark Aartsen ◽  
Markus Ackermann ◽  
Jenni Adams ◽  
Juan Antonio Aguilar ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Neutrino Flux ◽  
High Energy ◽  
Time Variable ◽  
Neutrino Emission ◽  
High Energy Neutrino ◽  
Excess Emission ◽  
Energy Neutrino ◽  
Variable Flux ◽  
Astrophysical Neutrino

A high-energy neutrino event detected by IceCube on 22 September 2017 was coincident in direction and time with a gamma-ray flare from the blazar TXS 0506+056. Prompted by this association, we investigated 9.5 years of IceCube neutrino observations to search for excess emission at the position of the blazar. We found an excess of high-energy neutrino events, with respect to atmospheric backgrounds, at that position between September 2014 and March 2015. Allowing for time-variable flux, this constitutes 3.5σ evidence for neutrino emission from the direction of TXS 0506+056, independent of and prior to the 2017 flaring episode. This suggests that blazars are identifiable sources of the high-energy astrophysical neutrino flux.

scholarly journals Estimating the impact of the QCD dynamics on the determination of the high energy astrophysical neutrino flux

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Victor P. Gonçalves ◽  
Diego R. Gratieri ◽  
Alex S. C. Quadros
Keyword(s):  
Maximum Likelihood ◽  
Cross Section ◽  
Neutrino Flux ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energies ◽  
Ultra High Energy Neutrinos ◽  
The Impact ◽  
Astrophysical Neutrino

AbstractThe number of ultra-high energy neutrinos arriving at IceCube depends on the energy dependence of the astrophysical neutrino flux and neutrino cross-section. In this paper, we investigate the impact of different assumptions for the description of the QCD dynamics at high energies on the determination of the normalization $$\Phi _{Astro}$$ Φ Astro and spectral index $$\gamma $$ γ of the astrophysical neutrino flux. The distribution of neutrino events at the IceCube is estimated considering the DGLAP, BFKL, CGC and BBMT approaches and the best estimates for $$\Phi _{Astro}$$ Φ Astro and $$\gamma $$ γ are determined using a maximum likelihood fit comparing the predictions with the distribution of observed events at IceCube. Moreover, we also investigate if the increase in the effective exposure time expected in IceCube-Gen2 will to allow us to disentangle the QCD dynamical effects from the description of the astrophysical neutrino flux.

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