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 SEARCH FOR NEUTRINO EMISSION FROM GAMMA-RAY SOURCES WITH THE ANTARES TELESCOPE

2012 ◽  
Vol 08 ◽  
pp. 307-310
Author(s):  
C. BIGONGIARI
Keyword(s):  
Gamma Ray ◽  
Neutrino Flux ◽  
Three Dimensional ◽  
Effective Area ◽  
High Energy ◽  
Neutrino Telescope ◽  
Neutrino Detector ◽  
Upper Limits ◽  
Cosmic Neutrino ◽  
Promising Source

ANTARES is the first undersea neutrino detector ever built and presently the neutrino telescope with the largest effective area operating in the Northern Hemisphere. A three-dimensional array of photomultiplier tubes detects the Cherenkov light induced by the muons produced in the interaction of high energy neutrinos with the matter surrounding the detector. The detection of astronomical neutrino sources is one of the main goals of ANTARES. The search for point-like neutrino sources with the ANTARES telescope is described and the preliminary results obtained with data collected from 2007 to 2010 are shown. No cosmic neutrino source has been observed and neutrino flux upper limits have been calculated for the most promising source candidates.

INVESTIGATION ON THE NEUTRINO INDUCED MUONS FROM ACTIVE GALACTIC NUCLEI

2000 ◽  
Vol 15 (25) ◽  
pp. 1567-1576
Author(s):  
NAYANTARA GUPTA ◽  
D. P. BHATTACHARYYA
Keyword(s):  
Cross Sections ◽  
Neutrino Flux ◽  
High Energy ◽  
Energy Spectra ◽  
Muon Energy ◽  
Model Calculations ◽  
Charge Current ◽  
Upper Limits ◽  
Total Interaction ◽  
Interaction Cross Sections

The fluxes of neutrino induced muons at different zenith angles have been calculated using the high energy diffused neutrino spectra emitted from blazars. We have used the standard formulation developed by Gaisser based on charge-current interactions in rock and the QED-based energy loss formulation to estimate the spectra of neutrino induced muons. The energy spectra of neutrino flux generated from blazars has been taken from the model calculations of Protheroe. The latest charge-current and total interaction cross-sections at ultrahigh energies from Kwiecinski et al. have been used to find the probability of muon generation from neutrinos and the loss of neutrinos during propagation through the Earth. We find that our derived horizontal neutrino induced muon energy spectra expected from blazar model of Protheroe is comparable with the upper limits as predicted by SOUDAN 2 experiment.

scholarly journals Follow-up of the IceCube alerts with the Baikal-GVD telescope

2021 ◽  
Vol 16 (11) ◽  
pp. C11008
Author(s):  
V.Y. Dik ◽  
V.A. Allakhverdyan ◽  
A.D. Avrorin ◽  
A.V. Avrorin ◽  
V.M. Aynutdinov ◽  
...  
Keyword(s):  
Time Windows ◽  
High Energy ◽  
Muon Neutrino ◽  
Significant Excess ◽  
Expected Number ◽  
Online Mode ◽  
High Energy Muon ◽  
Upper Limits ◽  
Background Events

Abstract The high-energy muon neutrino events of the IceCube telescope, that are triggered as neutrino alerts in one of two probability ranks of astrophysical origin, “gold” and “bronze”, have been followed up by the Baikal-GVD in a fast quasi-online mode since September 2020. Search for correlations between alerts and GVD events reconstructed in two modes, muon-track and cascades (electromagnetic or hadronic showers), for the time windows ±1 h and ±12 h does not indicate statistically significant excess of the measured events over the expected number of background events. Upper limits on the neutrino fluence will be presented for each alert.

scholarly journals Search for point sources of ultra-high-energy photons with the Telescope Array surface detector

2020 ◽  
Vol 492 (3) ◽  
pp. 3984-3993 ◽  
Author(s):  
R U Abbasi ◽  
M Abe ◽  
T Abu-Zayyad ◽  
M Allen ◽  
R Azuma ◽  
...  
Keyword(s):  
Point Source ◽  
Cosmic Ray ◽  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
Telescope Array ◽  
Air Shower ◽  
Upper Limits ◽  
Surface Detector ◽  
Blind Search

ABSTRACT The surface detector (SD) of the Telescope Array (TA) experiment allows us to detect indirectly photons with energies of the order of 1018 eV and higher, and to separate photons from the cosmic ray background. In this paper, we present the results of a blind search for point sources of ultra-high-energy (UHE) photons in the Northern sky using the TA SD data. The photon-induced extensive air showers are separated from the hadron-induced extensive air shower background by means of a multivariate classifier based upon 16 parameters that characterize the air shower events. No significant evidence for the photon point sources is found. The upper limits are set on the flux of photons from each particular direction in the sky within the TA field of view, according to the experiment’s angular resolution for photons. The average 95 per cent confidence level upper-limits for the point-source flux of photons with energies greater than 1018, 1018.5, 1019, 1019.5 and 1020 eV are 0.094, 0.029, 0.010, 0.0073 and 0.0058 km−2yr−1, respectively. For energies higher than 1018.5 eV, the photon point-source limits are set for the first time. Numerical results for each given direction in each energy range are provided as a supplement to this paper.

scholarly journals Review of observational results on γ-ray background: (Invited discourse)

1970 ◽  
Vol 37 ◽  
pp. 269-279 ◽  
Author(s):  
G. W. Clark ◽  
G. P. Garmire ◽  
W. L. Kraushaar
Keyword(s):  
Power Law ◽  
Strong Evidence ◽  
Galactic Plane ◽  
High Energy ◽  
Electromagnetic Spectrum ◽  
Γ Rays ◽  
Γ Ray ◽  
Region 10

Recent observations in the X- and γ-Ray region of the electromagnetic spectrum have given strong evidence for the existence of an extragalactic intensity with a slowly steepening power law spectrum in the region 103 to 108 eV. Further data from the OSO-III high energy γ-Ray detector are in agreement with earlier published reports, and suggest that the γ-Rays from high galactic latitudes have a softer spectrum than those from the galactic plane.

scholarly journals Recent Results from the Antares Neutrino Telescope

2019 ◽  
Vol 207 ◽  
pp. 01001
Author(s):  
Antoine Kouchner
Keyword(s):  
Galactic Plane ◽  
Large Fraction ◽  
Neutrino Flux ◽  
High Energy ◽  
Neutrino Telescope ◽  
Point Sources ◽  
Joint Analysis ◽  
Neutrino Source ◽  
Cosmic Neutrino ◽  
The One

Antares, the first undersea neutrino telescope, has been continuously operating since 2007 in the Mediterranean Sea. The transparency of the water allows for a very good angular resolution in the reconstruction of neutrino events of all flavors. This results in an unmatched sensitivity for neutrino source searches, in a large fraction of the Southern Sky, at TeV energies. As a consequence, Antares provides valuable constraints on the origin of the cosmic neutrino flux discovered by the IceCube Collaboration. Based on an all-flavor dataset spanning nine years of operation of the detector, the latest results of Antares searches for neutrino point sources, and for diffuse neutrino emission from the entire sky as well as from several interesting regions such as the Galactic Plane, are presented. Several results have been obtained through a joint analysis with the IceCube Collaboration. Concerning the multi-messenger program, the focus is made on the follow-up searches of IceCube alerts, in particular the one related to the TXS 0506+056 blazar, thought to be the first extragalactic high-energy neutrino source identified so far.

scholarly journals THE FSRQs 3C 279 AND PKS 1510-089: MAGIC LATEST RESULTS AND MULTIWAVELENGTH OBSERVATIONS

2014 ◽  
Vol 28 ◽  
pp. 1460176 ◽  
Author(s):  
◽  
G. DE CANEVA ◽  
U. BARRES DE ALMEIDA ◽  
E. LINDFORS ◽  
K. SAITO ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
X Rays ◽  
Spectrum Radio ◽  
Upper Limits ◽  
Very High Energy ◽  
Γ Rays ◽  
Differential Flux ◽  
Multiwavelength Observations

At very high energy (VHE, E> 100 GeV), we count only three blazars of the flat spectrum radio quasars (FSRQs) type to date. The MAGIC experiment detected all three of them; here we present MAGIC observations of 3C 279 and PKS 1510-089. 3C 279 was observed in 2011, without a significant detection, hence upper limits on the differential flux have been computed. The MAGIC observations of PKS 1510-089 in 2012 were triggered by alerts of high activity states and resulted in a significant detection. MAGIC observations are complemented with simultaneous multiwavelength observations in high energy γ rays, X-rays, optical and radio wavelengths and polarization measurements. With the study of the spectral features and the variability observed, we aim to identify the physical processes responsible for the behavior of this source class. In particular, we propose coherent scenarios, which take into account both the modeling of the spectral energy distribution and the constraints obtained from the lightcurves.

scholarly journals Search for transient optical counterparts to high-energy IceCube neutrinos with Pan-STARRS1

2019 ◽  
Vol 626 ◽  
pp. A117 ◽  
Author(s):  
◽  
E. Kankare ◽  
M. Huber ◽  
S. J. Smartt ◽  
K. Chambers ◽  
...  
Keyword(s):  
Light Curve ◽  
Neutrino Flux ◽  
High Energy ◽  
Random Coincidence ◽  
High Energy Neutrino ◽  
Energy Neutrino ◽  
Type Ia ◽  
Energy Type ◽  
Optical Transient

In order to identify the sources of the observed diffuse high-energy neutrino flux, it is crucial to discover their electromagnetic counterparts. To increase the sensitivity of detecting counterparts of transient or variable sources by telescopes with a limited field of view, IceCube began releasing alerts for single high-energy (Eν >  60 TeV) neutrino detections with sky localisation regions of order 1° radius in 2016. We used Pan-STARRS1 to follow-up five of these alerts during 2016–2017 to search for any optical transients that may be related to the neutrinos. Typically 10–20 faint (miP1 ≲ 22.5 mag) extragalactic transients are found within the Pan-STARRS1 footprints and are generally consistent with being unrelated field supernovae (SNe) and AGN. We looked for unusual properties of the detected transients, such as temporal coincidence of explosion epoch with the IceCube timestamp, or other peculiar light curve and physical properties. We found only one transient that had properties worthy of a specific follow-up. In the Pan-STARRS1 imaging for IceCube-160427A (probability to be of astrophysical origin of ∼50%), we found a SN PS16cgx, located at 10.0′ from the nominal IceCube direction. Spectroscopic observations of PS16cgx showed that it was an H-poor SN at redshift z = 0.2895 ± 0.0001. The spectra and light curve resemble some high-energy Type Ic SNe, raising the possibility of a jet driven SN with an explosion epoch temporally coincident with the neutrino detection. However, distinguishing Type Ia and Type Ic SNe at this redshift is notoriously difficult. Based on all available data we conclude that the transient is more likely to be a Type Ia with relatively weak Si II absorption and a fairly normal rest-frame r-band light curve. If, as predicted, there is no high-energy neutrino emission from Type Ia SNe, then PS16cgx must be a random coincidence, and unrelated to the IceCube-160427A. We find no other plausible optical transient for any of the five IceCube events observed down to a 5σ limiting magnitude of miP1 ≈ 22 mag, between 1 day and 25 days after detection.

scholarly journals Centaurus A: Hard X-ray and High-Energy Gamma-Ray Light Curve Correlation

Galaxies ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 44 ◽  
Author(s):  
Isak Davids ◽  
Markus Böttcher ◽  
Michael Backes
Keyword(s):  
Light Curve ◽  
High Energy ◽  
Electromagnetic Spectrum ◽  
X Rays ◽  
X Ray ◽  
Correlation Studies ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
Γ Rays ◽  
Centaurus A

Centaurus A, powered by a 55 million solar mass supermassive black hole, has been intensively monitored in all accessible wavelength ranges of the electromagnetic spectrum. However, its very-high energy gamma ( γ ) ray flux (TeV photons), obtained from H.E.S.S. is relatively faint, hampering detailed light curve analyses in the most energetic energy band. Yet, the extensive long-term light curve data from Fermi-LAT and Swift-BAT (hard X-rays) allows for cross-correlation studies. We find a hint that X-ray emission from Centaurus A precedes the γ rays by 25 ± 125 days. If this lag is real and related to a γ γ absorption effect in the broad-line region (BLR) around the central source, we can constrain the size of the BLR using light-travel time arguments. These are first results of extended light curve correlation studies between high-energy γ rays and X-rays from Centaurus A.

scholarly journals Search for High Energy emission from GRBs with MAGIC

2016 ◽  
Vol 12 (S324) ◽  
pp. 70-73
Author(s):  
Alessio Berti ◽  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Cherenkov Telescopes ◽  
Gamma Ray Imaging ◽  
Very High Energy ◽  
Γ Rays ◽  
High Energy Emission ◽  
The Universe ◽  
Very High

AbstractGamma-Ray Bursts (GRBs) are the most violent explosions in the Universe, releasing a huge amount of energy in few seconds. While our understanding of the prompt and the afterglow phases has increased with Swift and Fermi, we have very few information about their High Energy (HE, E ≲ 100) emission components. This requires a ground-based experiment able to perform fast follow-up with enough sensitivity above ~ 50 GeV. The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes have been designed to perform fast follow-up on GRBs thanks to fast slewing movement and low energy threshold (~ 50 GeV). Since the beginning of the operations, MAGIC followed-up 89 GRBs in good observational conditions. In this contribution the MAGIC GRBs follow-up campaign and the results which could be obtained by detecting HE and Very High Energy (VHE, E ≳ 100 GeV) γ-rays from GRBs will be reviewed.

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