A new and improved IceCube point source analysis

2021 ◽  
Vol 16 (11) ◽  
pp. C11002
Author(s):  
C. Bellenghi ◽  
T. Glauch ◽  
C. Haack ◽  
T. Kontrimas ◽  
H. Niederhausen ◽  
...  
Keyword(s):  
Point Source ◽  
High Energy ◽  
Source Analysis ◽  
Arrival Direction ◽  
Accurate Analysis ◽  
New Approach ◽  
Diffuse Flux ◽  
Astrophysical Neutrinos ◽  
Discovery Potential ◽  
Hard Spectrum

Abstract The IceCube Neutrino Observatory, a cubic kilometer scale Cherenkov detector deployed in the deep ice at the geographic South Pole, investigates extreme astrophysical phenomena by studying the corresponding high-energy neutrino signal. Its discovery of a diffuse flux of astrophysical neutrinos with energies up to the PeV scale in 2013 has triggered a vast effort to identify the mostly unknown sources of these high energy neutrinos. Here, we present a new IceCube point-source search that improves the accuracy of the statistical analysis, especially at energies of a few TeV and below. The new approach is based on multidimensional kernel density estimation for the probability density functions and new estimators for the observables, namely the reconstructed energy and the estimated angular uncertainty on the reconstructed arrival direction. The more accurate analysis provides an improvement in discovery potential up to ∼30% over previous works for hard spectrum sources.

scholarly journals THE BAIKAL NEUTRINO TELESCOPE — RESULTS AND PLANS

2005 ◽  
Vol 20 (29) ◽  
pp. 6932-6936 ◽  
Author(s):  
◽  
RALF WISCHNEWSKI ◽  
V. AYNUTDINOV ◽  
V. BALKANOV ◽  
I. BELOLAPTIKOV ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
High Energy ◽  
Neutrino Telescope ◽  
Muon Neutrino ◽  
Effective Volume ◽  
Diffuse Flux ◽  
High Energy Muon ◽  
Astrophysical Neutrinos

New results from the Baikal neutrino telescope NT200, based on the first 5 years of operation (1998–2003), are presented. We derive an all-flavor limit on the diffuse flux of astrophysical neutrinos between 20 TeV and 50 PeV, extract an enlarged sample of high energy muon neutrino events, and obtain limits on the flux of high energy atmospheric muons. In 2005, the upgraded telescope NT200+ will be commissioned: 3 additional distant strings with only 12 photo-multipliers each will rise the effective volume to 20 Mton at 10 PeV for this largest running neutrino telescope in the Northern hemisphere.

scholarly journals The Search for Neutrinos from TXS 0506+056 with the ANTARES Telescope

2019 ◽  
Vol 207 ◽  
pp. 02004
Author(s):  
Giulia Illuminati
Keyword(s):  
Point Source ◽  
Neutrino Flux ◽  
High Energy ◽  
Time Dependent ◽  
Source Analysis ◽  
Electromagnetic Spectrum ◽  
Upper Limits ◽  
Γ Rays ◽  
The One

A high-energy neutrino, IC170922A, detected by the IceCube experiment was found to be positionally coincident with the direction of a known blazar, TXS 0506+056, observed in γ-rays and at other wavelengths of the electromagnetic spectrum. Here, we present the results of three different searches for neutrino candidates, associated either with the IC170922A event or with the TXS 0506+056 blazar, performed by the ANTARES Collaboration. The three searches, an online follow-up of the IceCube alert, a standard time-integrated point-source analysis and a time-dependent search, yielded no significant observation. Consequently, 90% C.L. upper limits on the one-flavour neutrino flux and fluence have been derived.

scholarly journals Methods for point source analysis in high energy neutrino telescopes

2008 ◽  
Vol 29 (4) ◽  
pp. 299-305 ◽  
Author(s):  
Jim Braun ◽  
Jon Dumm ◽  
Francesco De Palma ◽  
Chad Finley ◽  
Albrecht Karle ◽  
...  
Keyword(s):  
Point Source ◽  
High Energy ◽  
Source Analysis ◽  
High Energy Neutrino ◽  
Neutrino Telescopes ◽  
Energy Neutrino

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

scholarly journals Unimodular vs nilpotent superfield approach to pure dS supergravity

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sukruti Bansal ◽  
Silvia Nagy ◽  
Antonio Padilla ◽  
Ivonne Zavala
Keyword(s):  
String Theory ◽  
General Framework ◽  
Recent Progress ◽  
High Energy ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
New Approach ◽  
Sitter Spacetime ◽  
Novel Approach ◽  
De Sitter Vacua

Abstract Recent progress in understanding de Sitter spacetime in supergravity and string theory has led to the development of a four dimensional supergravity with spontaneously broken supersymmetry allowing for de Sitter vacua, also called de Sitter supergravity. One approach makes use of constrained (nilpotent) superfields, while an alternative one couples supergravity to a locally supersymmetric generalization of the Volkov-Akulov goldstino action. These two approaches have been shown to give rise to the same 4D action. A novel approach to de Sitter vacua in supergravity involves the generalisation of unimodular gravity to supergravity using a super-Stückelberg mechanism. In this paper, we make a connection between this new approach and the previous two which are in the context of nilpotent superfields and the goldstino brane. We show that upon appropriate field redefinitions, the 4D actions match up to the cubic order in the fields. This points at the possible existence of a more general framework to obtain de Sitter spacetimes from high-energy theories.

scholarly journals Introducing the HD+B model for pulsar wind nebulae: a hybrid hydrodynamics/radiative approach

2020 ◽  
Vol 494 (3) ◽  
pp. 4357-4370
Author(s):  
B Olmi ◽  
D F Torres
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Theoretical Modelling ◽  
X Rays ◽  
Pulsar Wind Nebulae ◽  
New Approach ◽  
Energy Gamma ◽  
Radiative Model ◽  
Pulsar Wind

ABSTRACT Identification and characterization of a rapidly increasing number of pulsar wind nebulae is, and will continue to be, a challenge of high-energy gamma-ray astrophysics. Given that such systems constitute -by far- the most numerous expected population in the TeV regime, such characterization is important not only to learn about the sources per se from an individual and population perspective, but also to be able to connect them with observations at other frequencies, especially in radio and X-rays. Also, we need to remove the emission from nebulae in highly confused regions of the sky for revealing other underlying emitters. In this paper, we present a new approach for theoretical modelling of pulsar wind nebulae: a hybrid hydrodynamic-radiative model able to reproduce morphological features and spectra of the sources, with relatively limited numerical cost.

scholarly journals Neutrino Astronomy with IceCube

2016 ◽  
Vol 12 (S324) ◽  
pp. 322-329
Author(s):  
Kevin J. Meagher
Keyword(s):  
Real Time ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Galactic Nuclei ◽  
High Energy ◽  
Glacial Ice ◽  
Astrophysical Neutrinos ◽  
Charged Secondary ◽  
Neutrino Astronomy ◽  
The Antarctic

AbstractThe IceCube Neutrino Observatory is a cubic kilometer neutrino telescope located at the Geographic South Pole. Cherenkov radiation emitted by charged secondary particles from neutrino interactions is observed by IceCube using an array of 5160 photomultiplier tubes embedded between a depth of 1.5 km to 2.5 km in the Antarctic glacial ice. The detection of astrophysical neutrinos is a primary goal of IceCube and has now been realized with the discovery of a diffuse, high-energy flux consisting of neutrino events from tens of TeV up to several PeV. Many analyses have been performed to identify the source of these neutrinos: correlations with active galactic nuclei, gamma-ray bursts, and the galactic plane. IceCube also conducts multi-messenger campaigns to alert other observatories of possible neutrino transients in real-time. However, the source of these neutrinos remains elusive as no corresponding electromagnetic counterparts have been identified. This proceeding will give an overview of the detection principles of IceCube, the properties of the observed astrophysical neutrinos, the search for corresponding sources (including real-time searches), and plans for a next-generation neutrino detector, IceCube–Gen2.

A new approach to predict the strength of high energy materials

2011 ◽  
Vol 186 (1) ◽  
pp. 175-181 ◽  
Author(s):  
Mohammad Hossein Keshavarz ◽  
Mohammad Ghorbanifaraz ◽  
Hadi Rahimi ◽  
Mehdi Rahmani
Keyword(s):  
High Energy ◽  
Energy Materials ◽  
New Approach ◽  
High Energy Materials

scholarly journals Recent Results from IceCube

2018 ◽  
Vol 46 ◽  
pp. 1860048 ◽  
Author(s):  
Dawn Williams
Keyword(s):  
Energy Range ◽  
Neutrino Oscillation ◽  
Atmospheric Neutrino ◽  
High Energy ◽  
South Pole ◽  
Neutrino Interactions ◽  
Diffuse Flux ◽  
High Energy Neutrinos

The IceCube Neutrino Observatory is a cubic kilometer detector located at the geographic South Pole. IceCube was designed to detect high-energy neutrinos from cosmic sources, and the DeepCore extension of IceCube enables the study of atmospheric neutrino interactions down to energies of a few GeV. IceCube has detected a diffuse flux of neutrinos in the energy range from 100 TeV to several PeV, the properties of which are inconsistent with an atmospheric origin, and has also published competitive limits on atmospheric neutrino oscillation parameters and other neutrino properties. This paper presents the latest results from IceCube and prospects for future upgrades and expansions of the detector.

scholarly journals Estimates of European emissions of methyl chloroform using a Bayesian inversion method

2014 ◽  
Vol 14 (18) ◽  
pp. 9755-9770 ◽  
Author(s):  
M. Maione ◽  
F. Graziosi ◽  
J. Arduini ◽  
F. Furlani ◽  
U. Giostra ◽  
...  
Keyword(s):  
Point Source ◽  
High Frequency ◽  
Stratospheric Ozone ◽  
Montreal Protocol ◽  
Source Analysis ◽  
Bayesian Inversion ◽  
Inversion Method ◽  
Data Set ◽  
Methyl Chloroform

Abstract. Methyl chloroform (MCF) is a man-made chlorinated solvent contributing to the destruction of stratospheric ozone and is controlled under the "Montreal Protocol on Substances that Deplete the Ozone Layer" and its amendments, which called for its phase-out in 1996 in developed countries and 2015 in developing countries. Long-term, high-frequency observations of MCF carried out at three European sites show a constant decline in the background mixing ratios of MCF. However, we observe persistent non-negligible mixing ratio enhancements of MCF in pollution episodes, suggesting unexpectedly high ongoing emissions in Europe. In order to identify the source regions and to give an estimate of the magnitude of such emissions, we have used a Bayesian inversion method and a point source analysis, based on high-frequency long-term observations at the three European sites. The inversion identified southeastern France (SEF) as a region with enhanced MCF emissions. This estimate was confirmed by the point source analysis. We performed this analysis using an 11-year data set, from January 2002 to December 2012. Overall, emissions estimated for the European study domain decreased nearly exponentially from 1.1 Gg yr−1 in 2002 to 0.32 Gg yr−1 in 2012, of which the estimated emissions from the SEF region accounted for 0.49 Gg yr−1 in 2002 and 0.20 Gg yr−1 in 2012. The European estimates are a significant fraction of the total semi-hemisphere (30–90° N) emissions, contributing a minimum of 9.8% in 2004 and a maximum of 33.7% in 2011, of which on average 50% are from the SEF region. On the global scale, the SEF region is thus responsible for a minimum of 2.6% (in 2003) and a maximum of 10.3% (in 2009) of the global MCF emissions.

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