Search results for "methods [Gene Expression Profiling]"
showing 10 items of 838 documents
Astrophysical muon neutrino flux in the northern sky with 2 years of IceCube data
2015
Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of νe and ντ charged-current and neutral-current (cascade) neutrino interactions. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed.
Search for contained neutrino events at energies above 30 TeV in 2 years of data
2013
Neutrino observations are a unique probe of the universe's highest energy phenomena: neutrinos are able to escape from dense environments that photons cannot and are unambiguous tracers of hadronic interaction processes, in particular the acceleration of cosmic rays. We report on results of an all-sky search for these neutrinos at energies above 30 TeV in the cubic kilometer antarctic IceCube observatory between May 2010 and May 2012. The search follows up on the previous detection of two PeV neutrino events, with improved sensitivity and extended energy coverage down to approximately 30 TeV.
Search for contained neutrino events at energies greater than 1 TeV in 2 years of data
2015
The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV--PeV) neutrinos produced in distant astrophysical objects. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010--2012. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum,as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere.
Search for sterile neutrinos with one year of IceCube data
2016
The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy to search for the oscillation signatures of light sterile neutrinos. The primary result of this search derives from the first year of data, taken during 2011, of the full 86-string IceCube configuration.
Search for a diffuse flux of high-energy ¿µ with the ANTARES neutrino telescope
2011
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A $(0.83\times 2\pi)$ sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an $E^{-2}$ flux spectrum, a 90% c.l. upper limit on the diffuse $\nu_\mu$ flux of $E^2\Phi_{90%} = 5.3 \times 10^{-8} \ \mathrm{GeV\ cm^{-2}\ s^{-1}\ sr^{-1}} $ in the energy range 20 TeV - 2.5 PeV is obtained. Other signal models with differ…
The advanced Virgo longitudinal control system for the O2 observing run
2020
Following a successful period of data-taking between 2006 and 2011, the Virgo gravitational-wave detector was taken offline for a major upgrade. The changes made to the instrument significantly increased the complexity of the control systems and meant that an extended period of commissioning was required to reach a sensitivity appropriate for science data-taking. This commissioning period was completed in July of 2017 and the second-generation Advanced Virgo detector went on to join the Advanced LIGO detectors in the O2 science run in August of the same year. The upgraded detector was approximately twice as sensitive to binary neutron star mergers as the first-generation instrument. During …
Inference of proto-neutron star properties from gravitational-wave data in core-collapse supernovae
2021
The eventual detection of gravitational waves from core-collapse supernovae (CCSN) will help improve our current understanding of the explosion mechanism of massive stars. The stochastic nature of the late post-bounce gravitational wave signal due to the non-linear dynamics of the matter involved and the large number of degrees of freedom of the phenomenon make the source parameter inference problem very challenging. In this paper we take a step towards that goal and present a parameter estimation approach which is based on the gravitational waves associated with oscillations of proto-neutron stars (PNS). Numerical simulations of CCSN have shown that buoyancy-driven g-modes are responsible …
TANAMI II. Additional sources
2018
TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30{deg} declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and {gamma}-ray studies. We have previously published first-epoch 8.4GHz VLBI images of the parsec-scale structure of the initial sample. In this paper, we present images of 39 additional sources. The full sample comprises most of the radio- and {gamma}-ray brightest AGN in the southern quarter of the sky, overlapping with the region from which high-energy (>100TeV) neutrino events have been found. We characterize the parsec-scale radio properties of the jets and compare with the quasi-s…
Neutrinos from GRBs with ANTARES
2013
A search for muon neutrinos in coincidence with gamma-ray bursts with the ANTARES neutrino detector using data from the end of 2007 to 2011 is performed. Expected neutrino fluxes are calculated for each burst individually. The most recent numerical calculations of the spectra using the NeuCosmA code are employed, which include Monte Carlo simulations of the full underlying photohadronic interaction processes. The discovery probability for a selection of 296 gamma-ray bursts in the given period is optimised using an extended maximum-likelihood strategy. No significant excess over background is found in the data, and 90% confidence level upper limits are placed on the total expected flux acco…
Baryon Acoustic Oscillations in LRGs
2012
Baryon Acoustic Oscillations (BAO) have been previously detected using correlation functions and power spectra of the galaxy distribution. In this work, we present a new method for the detection of the real-space structures associated with this feature. These baryon acoustic structures are spherical shells with a relatively small density contrast, surrounding high density central regions. We design a specific wavelet adapted to the search for shells, and exploit the physics of the process by making use of two different mass tracers, introducing a specific statistic to detect the BAO features. We apply our method to the detection of BAO in a galaxy sample drawn from the Sloan Digital Sky Sur…