Search For High-energy Neutrinos Research Articles

Consistency of Lorentz-invariance violation neutrino scenarios in time delay analyses

Modifications inspired by quantum gravity in the kinematics of special relativity can manifest in various ways, including anomalies in the time of flight of massless particles and the emergence of decay channels for otherwise stable particles. Typically, these effects are studied independently; however, it may be necessary to combine both to perform a consistent analysis. In this work, we study the interplay between time-of-flight anomalies and neutrino instability in the context of a flavour-independent high-energy Lorentz-invariance violation (LIV) in the neutrino sector. Ensuring compatibility between both types of effects imposes strong constraints on the existence of early neutrinos with energies exceeding a maximum value determined by the scale of new physics. Such constraints depend on the specific LIV scenario and should be integrated into searches for high-energy neutrinos from gamma-ray bursts exhibiting LIV time shifts.

Gravitational wave triggered searches for high-energy neutrinos from binary neutron star mergers: Prospects for next generation detectors

Gravitational wave triggered searches for high-energy neutrinos from binary neutron star mergers: Prospects for next generation detectors

Search for High-energy Neutrinos from Ultraluminous Infrared Galaxies with IceCube

Abstract Ultraluminous infrared galaxies (ULIRGs) have infrared luminosities L IR ≥ 1012 L ⊙, making them the most luminous objects in the infrared sky. These dusty objects are generally powered by starbursts with star formation rates that exceed 100 M ⊙ yr−1, possibly combined with a contribution from an active galactic nucleus. Such environments make ULIRGs plausible sources of astrophysical high-energy neutrinos, which can be observed by the IceCube Neutrino Observatory at the South Pole. We present a stacking search for high-energy neutrinos from a representative sample of 75 ULIRGs with redshift z ≤ 0.13 using 7.5 yr of IceCube data. The results are consistent with a background-only observation, yielding upper limits on the neutrino flux from these 75 ULIRGs. For an unbroken E −2.5 power-law spectrum, we report an upper limit on the stacked flux Φ ν μ + ν ¯ μ 90 % = 3.24 × 10 − 14 TeV − 1 cm − 2 s − 1 ( E / 10 TeV ) − 2.5 at 90% confidence level. In addition, we constrain the contribution of the ULIRG source population to the observed diffuse astrophysical neutrino flux as well as model predictions.

Searching for High-Energy Neutrinos from Ultra-Luminous Infrared Galaxies with IceCube

This work presents an IceCube search for high-energy neutrinos from Ultra-Luminous Infrared Galaxies (ULIRGs). ULIRGs are the most luminous infrared objects in the sky, with infrared luminosities exceeding 1012 solar luminosities. They are mainly powered by starbursts that exhibit star-formation rates larger than 100 solar masses per year. In addition, an active galactic nucleus (AGN) can also contribute significantly to the ULIRG luminosity output. The acceleration of hadrons, and consequently the production of neutrinos, can occur both in starburst and AGN environments. As such, ULIRGs form a source population that could be responsible for a significant fraction of the diffuse neutrino flux observed by IceCube. In this study we perform a stacking analysis on a representative sample of 75 ULIRGs with redshift z ≤ 0.13 using 7.5 years of IceCube data. We find no evidence for astrophysical neutrinos correlated with our selection of ULIRGs. We therefore compute upper limits on the contribution of the ULIRG source population to the diffuse neutrino observations, and also use these limits to constrain model predictions.

Constraints on heavy decaying dark matter with current gamma-ray measurements

Among the several strategies for indirect searches of dark matter, a very promising one is to look for the gamma-rays from decaying dark matter. Here we use the most up-to-date upper bounds on the gamma-ray flux from 105 to 1011 GeV, obtained from CASA-MIA, KASCADE, KASCADE-Grande, Pierre Auger Observatory, Telescope Array and EAS-MSU. We obtain global limits on dark matter lifetime in the range of masses m DM = [107-1015] GeV. We provide the bounds for a set of decay channels chosen as representatives. The constraints derived here are new and cover a region of the parameter space not yet explored. We compare our results with the projected constraints from future neutrino telescopes, in order to quantify the improvement that will be obtained by the complementary high-energy neutrino searches.

Phenomenology of magnetic black holes with electroweak-symmetric coronas

Magnetically charged black holes (MBHs) are interesting solutions of the Standard Model and general relativity. They may possess a “hairy” electroweak-symmetric corona outside the event horizon, which speeds up their Hawking radiation and leads them to become nearly extremal on short timescales. Their masses could range from the Planck scale up to the Earth mass. We study various methods to search for primordially produced MBHs and estimate the upper limits on their abundance. We revisit the Parker bound on magnetic monopoles and show that it can be extended by several orders of magnitude using the large-scale coherent magnetic fields in Andromeda. This sets a mass-independent constraint that MBHs have an abundance less than 4 × 10−4 times that of dark matter. MBHs can also be captured in astrophysical systems like the Sun, the Earth, or neutron stars. There, they can become non-extremal either from merging with an oppositely charged MBH or absorbing nucleons. The resulting Hawking radiation can be detected as neutri- nos, photons, or heat. High-energy neutrino searches in particular can set a stronger bound than the Parker bound for some MBH masses, down to an abundance 10−7 of dark matter.

Constraining the fraction of core-collapse supernovae harbouring choked jets with high-energy neutrinos

ABSTRACT The joint observation of core-collapse supernovae with gamma-ray bursts shows that jets can be launched in the aftermath of stellar core collapse, likely by a newly formed black hole that accretes matter from the star. Such gamma-ray bursts have only been observed accompanying Type Ibc supernovae, indicating a stellar progenitor that lost its hydrogen envelope before collapse. According to recent hypothesis, it is possible that jets are launched in core-collapse events even when the progenitors still retain their hydrogen envelopes; however, such jets are not able to burrow through the star and will be stalled into the interior of the progenitor star before escaping. These jets are called choked jets. High-energy neutrinos produced by such choked jets could escape the stellar envelope and could be observed. Here, we examine how multimessenger searches for high-energy neutrinos and core-collapse supernovae can detect or limit the fraction of stellar collapses that produce jets. We find that a high fraction of jet production is already limited by previous observational campaigns. We explore possibilities with future observations using Large Synoptic Survey Telescope, IceCube, and Km3NET.

Baikal-GVD: cascades

Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-megaton subarrays (clusters) and is designed for the detection of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The design of Baikal-GVD allows one to search for astrophysical neutrinos with flux values measured by IceCube already at early phases of the array construction. We present here preliminary results of the search for high-energy neutrinos via the cascade mode obtained in 2015 and 2016.

Search for High-Energy Neutrinos from GW170817 with the Baikal-GVD Neutrino Telescope

The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by Fermi-GBM and INTEGRAL, indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the TeV - 100 PeV energy range using Baikal-GVD. No neutrinos directionally coincident with the source were detected within $\pm$500 s around the merger time, as well as during a 14-day period after the GW detection. We derived 90% confidence level upper limits on the neutrino fluence from GW170817 during a $\pm$500 s window centered on the GW trigger time, and a 14-day window following the GW signal under the assumption of an $E^{-2}$ neutrino energy spectrum.

All-sky search for high-energy neutrinos from gravitational wave event GW170104 with the Antares\xa0neutrino telescope

Advanced LIGO detected a significant gravitational wave signal (GW170104) originating from the coalescence of two black holes during the second observation run on January 4th, 2017. An all-sky high-energy neutrino follow-up search has been made using data from the Antares neutrino telescope, including both upgoing and downgoing events in two separate analyses. No neutrino candidates were found within pm 500 s around the GW event time nor any time clustering of events over an extended time window of pm 3 months. The non-detection is used to constrain isotropic-equivalent high-energy neutrino emission from GW170104 to less than sim {1.2}times 10^{{55}} erg for a E^{-2} spectrum. This constraint is valid in the energy range corresponding to the 5–95% quantiles of the neutrino flux [3.2 TeV; 3.6 PeV], if the GW emitter was below the Antares horizon at the alert time.

Search for High-energy Neutrinos from Binary Neutron Star Merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory

The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by the Fermi Gamma-ray Burst Monitor (Fermi-GBM), and the Anticoincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the GeV--EeV energy range using the ANTARES, IceCube, and Pierre Auger Observatories. No neutrinos directionally coincident with the source were detected within $\pm500$ s around the merger time. Additionally, no MeV neutrino burst signal was detected coincident with the merger. We further carried out an extended search in the direction of the source for high-energy neutrinos within the 14-day period following the merger, but found no evidence of emission. We used these results to probe dissipation mechanisms in relativistic outflows driven by the binary neutron star merger. The non-detection is consistent with model predictions of short GRBs observed at a large off-axis angle.

Search for high energy neutrinos from bright GRBs with ANTARES

Gamma-ray bursts are thought to be cosmic-ray accelerators, thus neutrinos are expected from the decay of charged mesons, produced in pγ interactions. The search for high-energy neutrinos from astrophysical sources is one of the main goals of the ANTARES scientific project. The methods and the results of a search for neutrinos from the brightest GRBs observed between 2008 and 2013 are presented. Two scenarios of the fireball model have been investigated: the internal shock and the photospheric case. Since no events have been detected in time and space coincidence with any of these bursts, upper limits at 90% C.L. on the expected neutrino fluxes are derived, as well as constraints on some parameters used in the modeling of the neutrino yield, as the bulk Lorentz factor of the jet and the baryon loading fp.

High-Energy Neutrino Searches in the Mediterranean Sea: probing the Universe with antares and km3net-arca

antares is a first generation neutrino telescope, built in the deep sea. We present here its latest results, focusing on the constraints placed on the origin of the cosmic signal observed by the icecube detector. In parallel to the antares results, we discuss the expected performance of the next generation detector under construction in the Mediterranean Sea - km3net- and in particular its high-energy component arca.

Status of the scalar singlet dark matter model

One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a mathbb {Z}_2 symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above sim 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned.

Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find 2 and 4 neutrino candidates detected by IceCube, and 1 and 0 detected by ANTARES, within $\pm500$ s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use non-detection to constrain isotropic-equivalent high-energy neutrino emission from GW151226 adopting the GW event's 3D localization, to less than $2\times 10^{51}-2\times10^{54}$ erg.

Search for high-energy neutrinos from bright GRBs with ANTARES

Gamma-ray bursts are thought to be sites of hadronic acceleration, thus neutrinos are expected from the decay of charged particles, produced in p{\gamma} interactions. The methods and results of a search for muon neutrinos in the data of the ANTARES neutrino telescope from four bright GRBs (GRB 080916C, GRB 110918A, GRB 130427A and GRB 130505A) observed between 2008 and 2013 are presented. Two scenarios of the fireball model have been investigated: the internal shock scenario, leading to the production of neutrinos with energies mainly above 100 TeV, and the photospheric scenario, characterised by a low-energy component in neutrino spectra due to the assumption of neutrino production closer to the central engine. Since no neutrino events have been detected in temporal and spatial coincidence with these bursts, upper limits at 90% C.L. on the expected neutrino fluxes are derived. The non-detection allows for directly constraining the bulk Lorentz factor of the jet {\Gamma} and the baryon loading fp.

Search for high energy neutrinos from bright GRBs with ANTARES

Gamma-ray bursts are a possible site of hadronic acceleration, thus neutrinos are expected in correspondence of a GRB event. The brightest GRB observed between 2008 and 2013 (GRB080916C, GRB110918A, GRB130427A and GRB130505A) have been investigated using the data of the ANTARES high energy neutrino telescope. In this paper two of most promising models of the GRB neutrino emission will be studied: the internal shock model and the photospheric model. No muons have been measured in space and time correlation with the selected GRBs and upper limits at 90% C.L. on the expected neutrino fluxes have been derived. This measure allows also setting constraints on some parameters used in the modeling of the neutrino flux: the bulk Lorentz factor of the jet Г and the baryon loading f p .

Acoustic Search for High Energy Neutrinos in Lake Baikal: Status and Perspectives

We report theoretical and experimental results of on-going feasibility studies to detect cosmic neutrinos acoustically in Lake Baikal. In order to examine ambient noise conditions and to develop re- spective pulse detection techniques a prototype device was created. The device is operating at a depth of 150 m at the site of the Baikal Neutrino Telescope and is capable to detect and classify acoustic signals with different shapes, as well as signals from neutrino- induced showers.

A time-dependent search for high-energy neutrinos from bright GRBs with ANTARES

Astrophysical point-like neutrino sources, like Gamma-Ray Bursts (GRBs), are one of the main targets for neutrino telescopes, since they are among the best candidates for Ultra-High-Energy Cosmic Ray (UHECR) acceleration. From the interaction between the accelerated protons and the intense radiation fields of the source jet, charged mesons are produced, which then decay into neutrinos. The methods and the results of a search for high-energy neutrinos in spatial and temporal correlation with the detected gamma-ray emission are presented for four bright GRBs observed between 2008 and 2013: a time-dependent analysis, optimised for each flare of the selected bursts, is performed to predict detailed neutrino spectra. The internal shock scenario of the fireball model is investigated, relying on the neutrino spectra computed through the numerical code NeuCosmA. The analysis is optimized on a per burst basis, through the maximization of the signal discovery probability. Since no events in ANTARES data passed the optimised cuts, 90% C.L. upper limits are derived on the expected neutrino fluences.

Search for high-energy neutrinos from GRB130427A with the ANTARES neutrino telescope

ANTARES is the first deep under-sea high-energy astrophysical neutrino telescope, in operation since 2008, in the Northern Hemisphere. In the light of a multi-messenger approach, one of the most ever intense (photon fluence Fγ ≃10-3 erg/cm2) and close (redshift z = 0.34) transient γ-source, GRB130427A, is considered in the ANTARES physics program for a co-incident search for photons and high-energy neutrinos. The first time-dependent analysis on GRBs neutrino emissions has been performed for this source: Konus-Wind parameters of the γ time-dependent spectrum are used to predict the expected neutrino flux from each peak of the burst, through the numerical calculation code NeuCosmA. An extended maximum likelihood ratio search is performed in order to maximize the discovery probability of prompt neutrinos from the burst: at the end, ANTARES sensitivity to this source is evaluated to be E2Φv ∼ 1 -10 GeV/cm2 in the energy range from 2 x 105 GeV to 2 x 107 GeV.