293 research outputs found
Short term outcome after left atrial appendage occlusion with the AMPLATZER Amulet and WATCHMAN device: results from the ORIGINAL registry (saxOnian RegIstry analyzinG and followINg left atrial Appendage cLosure)
Background: Various randomized multicenter studies have shown that percutaneous left atrial appendage closure (LAAC) is not inferior in stroke prevention compared to vitamin K antagonists (VKA) and can be performed safely and effectively.
Aims: The prospective multicenter ORIGINAL registry in the Free State of Saxony (saxOnian RegIstry analyzinG and followINg left atrial Appendage cLosure) investigated the efficiency and safety of LAAC with Watchman or Amulet device in a real word setting. A special focus was put on the influence of LAAC frequency on periprocedural efficiency and safety.
Methods and results: The total of 482 consecutive patients (Abbott Amulet N = 93 and Boston Scientific Watchman N = 389) were included in the periinterventional analyses. After 6 weeks, 353 patients completed the first follow-up including transoesophageal echocardiography (TEE) (73.2%). Successful LAAC could be performed in more than 94%. The complication rate does not significantly differ between device types (p = 0.92) according to Fischer test and comprised 2.2% in the Amulet and 2.3% in the Watchman group. The kind of device and the frequency of LAAC per study center had no influence on the success and complication rates. Device related thrombus could be revealed more frequently in the Watchman group (4.5%) than in the Amulet group (1.4%) but this difference is still not significant in Fisher test (p = 0.14). Same conclusion can be made about residual leakage 1.1% versus 0% [not significant in Fisher test (p = 0.26)]. Dual antiplatelet therapy followed the intervention in 64% and 22% of patients were discharged under a combination of an anticoagulant (VKA/DOAC/Heparin) and one antiplatelet agent.
Conclusions: The ORIGINAL registry supports the thesis from large, randomized trials that LAAC can be performed with a very high procedural success rate in the everyday clinical routine irrespective of the used LAA device (Watchman or Amulet). The postprocedural antithrombotic strategy differs widely among the participating centers
Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing
We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011–2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2θ23=0.51±0.05 and Δm232=2.41±0.07×10−3 eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties
Limits on Neutrino Emission from GRB 221009A from MeV to PeV using the IceCube Neutrino Observatory
Gamma-ray bursts (GRBs) have long been considered a possible source of
high-energy neutrinos. While no correlations have yet been detected between
high-energy neutrinos and GRBs, the recent observation of GRB 221009A - the
brightest GRB observed by Fermi-GBM to date and the first one to be observed
above an energy of 10 TeV - provides a unique opportunity to test for hadronic
emission. In this paper, we leverage the wide energy range of the IceCube
Neutrino Observatory to search for neutrinos from GRB 221009A. We find no
significant deviation from background expectation across event samples ranging
from MeV to PeV energies, placing stringent upper limits on the neutrino
emission from this source.Comment: Version in ApJ Letters Focus on the Ultra-luminous Gamma-Ray Burst
GRB 221009
Constraining High-energy Neutrino Emission from Supernovae with IceCube
Core-collapse supernovae are a promising potential high-energy neutrino source class. We test for correlation between seven years of IceCube neutrino data and a catalog containing more than 1000 core-collapse supernovae of types IIn and IIP and a sample of stripped-envelope supernovae. We search both for neutrino emission from individual supernovae, and for combined emission from the whole supernova sample through a stacking analysis. No significant spatial or temporal correlation of neutrinos with the cataloged supernovae was found. The overall deviation of all tested scenarios from the background expectation yields a p-value of 93% which is fully compatible with background. The derived upper limits on the total energy emitted in neutrinos are 1.7×10 erg for stripped-envelope supernovae, 2.8×10 erg for type IIP, and 1.3×10 erg for type IIn SNe, the latter disfavouring models with optimistic assumptions for neutrino production in interacting supernovae. We conclude that strippe-envelope supernovae and supernovae of type IIn do not contribute more than 14.6% and 33.9% respectively to the diffuse neutrino flux in the energy range of about 10−10 GeV, assuming that the neutrino energy spectrum follows a power-law with an index of −2.5. Under the same assumption, we can only constrain the contribution of type IIP SNe to no more than 59.9%. Thus core-collapse supernovae of types IIn and stripped-envelope supernovae can both be ruled out as the dominant source of the diffuse neutrino flux under the given assumptions
IceCat-1: The IceCube Event Catalog of Alert Tracks
We present a catalog of likely astrophysical neutrino track-like events from the IceCube Neutrino Observatory. IceCube began reporting likely astrophysical neutrinos in 2016, and this system was updated in 2019. The catalog presented here includes events that were reported in real time since 2019, as well as events identified in archival data samples starting from 2011. We report 275 neutrino events from two selection channels as the first entries in the catalog, the IceCube Event Catalog of Alert Tracks, which will see ongoing extensions with additional alerts. The Gold and Bronze alert channels respectively provide neutrino candidates with a 50% and 30% probability of being astrophysical, on average assuming an astrophysical neutrino power-law energy spectral index of 2.19. For each neutrino alert, we provide the reconstructed energy, direction, false-alarm rate, probability of being astrophysical in origin, and likelihood contours describing the spatial uncertainty in the alert\u27s reconstructed location. We also investigate a directional correlation of these neutrino events with gamma-ray and X-ray catalogs, including 4FGL, 3HWC, TeVCat, and Swift-BAT
Constraining High-energy Neutrino Emission from Supernovae with IceCube
Core-collapse supernovae are a promising potential high-energy neutrino source class. We test for correlation between seven years of IceCube neutrino data and a catalog containing more than 1000 core-collapse supernovae of types IIn and IIP and a sample of stripped-envelope supernovae. We search both for neutrino emission from individual supernovae as well as for combined emission from the whole supernova sample, through a stacking analysis. No significant spatial or temporal correlation of neutrinos with the cataloged supernovae was found. All scenarios were tested against the background expectation and together yield an overall p-value of 93%; therefore, they show consistency with the background only. The derived upper limits on the total energy emitted in neutrinos are 1.7 × 10 erg for stripped-envelope supernovae, 2.8 × 10 erg for type IIP, and 1.3 × 10 erg for type IIn SNe, the latter disfavoring models with optimistic assumptions for neutrino production in interacting supernovae. We conclude that stripped-envelope supernovae and supernovae of type IIn do not contribute more than 14.6% and 33.9%, respectively, to the diffuse neutrino flux in the energy range of about [ 10–10] GeV, assuming that the neutrino energy spectrum follows a power-law with an index of −2.5. Under the same assumption, we can only constrain the contribution of type IIP SNe to no more than 59.9%. Thus, core-collapse supernovae of types IIn and stripped-envelope supernovae can both be ruled out as the dominant source of the diffuse neutrino flux under the given assumptions
Measurement of Atmospheric Neutrino Mixing with Improved IceCube DeepCore Calibration and Data Processing
We describe a new data sample of IceCube DeepCore and report on the latest
measurement of atmospheric neutrino oscillations obtained with data recorded
between 2011-2019. The sample includes significant improvements in data
calibration, detector simulation, and data processing, and the analysis
benefits from a detailed treatment of systematic uncertainties, with
significantly higher level of detail since our last study. By measuring the
relative fluxes of neutrino flavors as a function of their reconstructed
energies and arrival directions we constrain the atmospheric neutrino mixing
parameters to be and , assuming a normal mass ordering. The
resulting 40\% reduction in the error of both parameters with respect to our
previous result makes this the most precise measurement of oscillation
parameters using atmospheric neutrinos. Our results are also compatible and
complementary to those obtained using neutrino beams from accelerators, which
are obtained at lower neutrino energies and are subject to different sources of
uncertainties
A Search for IceCube sub-TeV Neutrinos Correlated with Gravitational-Wave Events Detected By LIGO/Virgo
The LIGO/Virgo collaboration published the catalogs GWTC-1, GWTC-2.1 and
GWTC-3 containing candidate gravitational-wave (GW) events detected during its
runs O1, O2 and O3. These GW events can be possible sites of neutrino emission.
In this paper, we present a search for neutrino counterparts of 90 GW
candidates using IceCube DeepCore, the low-energy infill array of the IceCube
Neutrino Observatory. The search is conducted using an unbinned maximum
likelihood method, within a time window of 1000 s and uses the spatial and
timing information from the GW events. The neutrinos used for the search have
energies ranging from a few GeV to several tens of TeV. We do not find any
significant emission of neutrinos, and place upper limits on the flux and the
isotropic-equivalent energy emitted in low-energy neutrinos. We also conduct a
binomial test to search for source populations potentially contributing to
neutrino emission. We report a non-detection of a significant neutrino-source
population with this test.Comment: Submitted to Ap
A Search for Coincident Neutrino Emission from Fast Radio Bursts with Seven Years of IceCube Cascade Events
This paper presents the results of a search for neutrinos that are spatially
and temporally coincident with 22 unique, non-repeating Fast Radio Bursts
(FRBs) and one repeating FRB (FRB121102). FRBs are a rapidly growing class of
Galactic and extragalactic astrophysical objects that are considered a
potential source of high-energy neutrinos. The IceCube Neutrino Observatory's
previous FRB analyses have solely used track events. This search utilizes seven
years of IceCube's cascade events which are statistically independent of the
track events. This event selection allows probing of a longer range of extended
timescales due to the low background rate. No statistically significant
clustering of neutrinos was observed. Upper limits are set on the
time-integrated neutrino flux emitted by FRBs for a range of extended
time-windows
- …