Search results for "Collapse"
showing 10 items of 159 documents
A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
2013
A search for high-energy neutrinos coming from the direction of the Sun has been performed using the data recorded by the ANTARES neutrino telescope during 2007 and 2008. The neutrino selection criteria have been chosen to maximize the selection of possible signals produced by the self-annihilation of weakly interacting massive particles accumulated in the centre of the Sun with respect to the atmospheric background. After data unblinding, the number of neutrinos observed towards the Sun was found to be compatible with background expectations. The 90% CL upper limits in terms of spin-dependent and spin-independent WIMP-proton cross-sections are derived and compared to predictions of two sup…
Search for Multimessenger Sources of Gravitational Waves and High-energy Neutrinos with Advanced LIGO during Its First Observing Run, ANTARES, and Ic…
2019
[EN] Astrophysical sources of gravitational waves, such as binary neutron star and black hole mergers or core-collapse supernovae, can drive relativistic outflows, giving rise to non-thermal high-energy emission. High-energy neutrinos are signatures of such outflows. The detection of gravitational waves and high-energy neutrinos from common sources could help establish the connection between the dynamics of the progenitor and the properties of the out¿ow. We searched for associated emission of gravitational waves and high-energy neutrinos from astrophysical transients with minimal assumptions using data from Advanced LIGO from its first observing run O1, and data from the ANTARES and IceCub…
Towards asteroseismology of core-collapse supernovae with gravitational-wave observations – I. Cowling approximation
2017
Gravitational waves from core-collapse supernovae are produced by the excitation of different oscillation modes in the protoneutron star (PNS) and its surroundings, including the shock. In this work we study the relationship between the post-bounce oscillation spectrum of the PNS–shock system and the characteristic frequencies observed in gravitational-wave signals from core-collapse simulations. This is a fundamental first step in order to develop a procedure to infer astrophysical parameters of the PNS formed in core-collapse supernovae. Our method combines information from the oscillation spectrum of the PNS, obtained through linear perturbation analysis in general relativity of a backgr…
Excision technique in constrained formulations of Einstein equations: collapse scenario
2015
We present a new excision technique used in constrained formulations of Einstein equations to deal with black hole in numerical simulations. We show the applicability of this scheme in several scenarios. In particular, we present the dynamical evolution of the collapse of a neutron star to a black hole, using the CoCoNuT code and this excision technique.
Search for Gravitational-wave Signals Associated with Gamma-Ray Bursts during the Second Observing Run of Advanced LIGO and Advanced Virgo
2019
We present the results of targeted searches for gravitational-wave transients associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from 2016 November to 2017 August. We have analyzed 98 gamma-ray bursts using an unmodeled search method that searches for generic transient gravitational waves and 42 with a modeled search method that targets compact-binary mergers as progenitors of short gamma-ray bursts. Both methods clearly detect the previously reported binary merger signal GW170817, with p-values of <9.38 10-6 (modeled) and 3.1 10-4 (unmodeled). We do not find any significant evidence for gravitational-wave signals associate…
ALMA spectral survey of Supernova 1987A – molecular inventory, chemistry, dynamics and explosive nucleosynthesis
2017
We report the first molecular line survey of Supernova 1987A in the millimetre wavelength range. In the ALMA 210--300 and 340--360 GHz spectra, we detected cold (20--170 K) CO, 28SiO, HCO+ and SO, with weaker lines of 29SiO from ejecta. This is the first identification of HCO+ and SO in a young supernova remnant. We find a dip in the J=6--5 and 5--4 SiO line profiles, suggesting that the ejecta morphology is likely elongated. The difference of the CO and SiO line profiles is consistent with hydrodynamic simulations, which show that Rayleigh-Taylor instabilities cause mixing of gas, with heavier elements much more disturbed, making more elongated structure. We obtained isotopologue ratios of…
Architecture and 15 ka to present volcano-tectono-sedimentary evolution of the Neapolitan Yellow Tuff caldera offshore the Campi Flegrei, (Naples, Ea…
2012
The Campi Flegrei area is structurally dominated by the caldera associated with the eruption of the Neapolitan Yellow Tuff (NYT), a 40 km3 DRE ignimbrite dated at ca 15 ka BP [Deino et al., 2004], The volcanological evolution of the NYT caldera as been long described on the basis of outcrop and subsurface studies onland [Rosi & Sbrana, 1987; Orsi et al., 1996, and references therein; Di Vito et al., 1999; Perrotta et al., 2006; Fedele et al., 2011], but its offshore morphology, the stratal geometry of the volcaniclastic products and structures and the late-stage geodynamic evolution of the inner caldera resurgence are still poorly known. We integrate geological and geophysical data obtained…
L'ANTICO CAMPANILE DELLA CATTEDRALE DI LECCE IN UN CONSULTO DEL 1574
2016
L'antico campanile della cattedrale di Lecce si trovava in una posizione diversa rispetto a quello esistente costruito nel 1658. La maestosa torre, con cinque ordini e una terminazione a corona, era collocata di fianco all'antica facciata principale della chiesa, sul lato sinistro. Nel 1574 a causa di numerosi crolli, gli amministratori della chiesa decisero di avvalersi del parere tecnico di tre professionisti: Padoano Schiero, Padoano Baxi e Gabriele Meschinello, chiamati ad esprimersi in merito alla pericolosità di tali crolli e allo stato della torre. Vennero prodotte tre relazioni tecniche i cui contenuti illustravano la necessità di demolire la torre al fine di scongiurare eventuali d…
Seismic expression of the shallow structure of The Neapolitan Yellow Tuff (NYT) caldera offshore the Campi Flegrei
2014
In this study we integrate high-resolution swath bathymetry, single-channel reflection seismic data and gravity core data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for a reconstruction of the offshore geometry of the NYT caldera collapse – ring fault system, along with the style and timing of deformation of the inner caldera resurgence. Our interpretation shows that the NYT eruption (~15 ka BP) was associated with a caldera collapse bounded by an inward-dipping ring fault system. The ring fault system consists in a …
The Neapolitan Yellow Tuff caldera offshore the Campi Flegrei: Stratal architecture and kinematic reconstruction during the last 15 ky
2014
In this study we integrate high-resolution swath bathymetry, single channel reflection seismic data and gravity core data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for a reconstruction of the offshore geometry of the NYT caldera collapse-ring fault system, along with the style and timing of deformation of the inner caldera resurgence.Our interpretation shows that the NYT eruption (~. 15. ka BP) was associated with a caldera collapse bounded by an inward-dipping ring fault system. The ring fault system consists in a …