Y. Bouffanais
A5082753294- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Atomic and Subatomic Physics Research
- Radio Astronomy Observations and Technology
- Statistical and numerical algorithms
- Seismic Waves and Analysis
- Geophysics and Sensor Technology
- Seismic Imaging and Inversion Techniques
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Cold Atom Physics and Bose-Einstein Condensates
- Superconducting Materials and Applications
- Seismology and Earthquake Studies
- earthquake and tectonic studies
- Neutrino Physics Research
- Galaxies: Formation, Evolution, Phenomena
- Gas Dynamics and Kinetic Theory
- Ocean Waves and Remote Sensing
University of Padua
2019-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2019-2023
Osservatorio Astronomico di Padova
2019-2022
Université Paris Cité
2016-2021
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2021
Centre National de la Recherche Scientifique
2016-2021
Délégation Paris 7
2016-2021
Sorbonne Paris Cité
2016-2021
Laboratoire AstroParticule et Cosmologie
2016-2021
Universitat de València
2019
The first observational run of the Advanced LIGO detectors, from September 12, 2015 to January 19, 2016, saw detections gravitational waves binary black hole mergers. In this paper we present full results a search for merger signals with total masses up $100 M_\odot$ and detailed implications our observations these systems. Our search, based on general-relativistic models wave systems, unambiguously identified two signals, GW150914 GW151226, significance greater than $5\sigma$ over observing...
Current interferometric gravitational-wave detectors are limited by quantum noise over a wide range of their measurement bandwidth. One method to overcome the limit is injection squeezed vacuum states light into interferometer's dark port. Here, we report on successful application this technology improve shot sensitivity Advanced Virgo detector. A enhancement up 3.2±0.1 dB beyond achieved. This nonclassical improvement corresponds 5%–8% increase binary neutron star horizon. The squeezing was...
Abstract We perform a statistical standard siren analysis of GW170817. Our does not utilize knowledge NGC 4993 as the unique host galaxy optical counterpart to Instead, we consider each within GW170817 localization region potential host; combining redshifts from all galaxies with distance estimate provides an Hubble constant, H 0 . Considering brighter than equally likely binary neutron star merger, find km s −1 Mpc (maximum posteriori and 68.3% highest density posterior interval; assuming...
ABSTRACT We report here the non-detection of gravitational waves from merger binary–neutron star systems and neutron star–black hole during first observing run Advanced Laser Interferometer Gravitational-wave Observatory (LIGO). In particular, we searched for gravitational-wave signals with component masses dimensionless spins <0.05. also same parameters, black mass , no restriction on spin magnitude. assess sensitivity two LIGO detectors to these find that they could have detected...
ABSTRACT We evaluate the redshift distribution of binary black hole (BBH), hole–neutron star (BHNS), and neutron (BNS) mergers, exploring main sources uncertainty: formation rate (SFR) density, metallicity evolution, common envelope, mass transfer via Roche lobe overflow, natal kicks, core-collapse supernova model, initial function. Among evolution processes, uncertainties on envelope ejection have a major impact: local merger density BNSs varies from ∼103 to ∼20 Gpc−3 yr−1 if we change...
ABSTRACT We explore hierarchical black hole (BH) mergers in nuclear star clusters (NSCs), globular (GCs) and young (YSCs), accounting for both original dynamically assembled binary BHs (BBHs). find that the median mass of first- nth-generation dynamical is larger GCs YSCs with respect to NSCs because lighter are ejected by supernova kicks from lower clusters. Also, BH masses strongly affected metallicity progenitor stars: primary a merger ∼24–38 M⊙ (∼9–15 M⊙) metal-poor (metal-rich) NSCs....
The growing population of binary black holes (BBHs) observed by gravitational wave detectors is a potential Rosetta stone for understanding their formation channels. Here, we use an upgraded version our semi-analytic codes {\sc fastcluster} and cosmo$\mathcal{R}$ate} to investigate the cosmic evolution four different BBH populations: isolated BBHs dynamically formed in nuclear star clusters (NSCs), globular (GCs), young (YSCs). With approach, can study channels assuming same stellar input...
This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) on September 14, 2015 [1]. Reference presented parameter estimation [2] using 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and 11-dimensional nonprecessing effective-one-body (EOB) calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing...
We compare GW150914 directly to simulations of coalescing binary black holes in full general relativity, accounting for all the spin-weighted quadrupolar modes, and separately octopolar modes. Consistent with posterior distributions reported LVC_PE[1] (at 90% confidence), we find data are compatible a wide range nonprecessing precessing simulations. Followup performed using previously-estimated parameters most resemble data. Comparisons including only modes constrain total redshifted mass Mz...
The first observing run of Advanced LIGO spanned 4 months, from September 12, 2015 to January 19, 2016, during which gravitational waves were directly detected two binary black hole systems, namely GW150914 and GW151226. Confident detection requires an understanding instrumental transients artifacts that can reduce the sensitivity a search. Studies quality detector data yield insights into cause vetoes specific search are produced mitigate effects problematic data. In this paper, systematic...
We investigate the impact of stellar rotation on formation black holes (BHs), by means our population-synthesis code SEVN. Rotation affects mass function BHs in several ways. In massive metal-poor stars, fast reduces minimum zero-age main sequence (ZAMS) for a star to undergo pair instability and pulsational instability. Moreover, winds are enhanced rotation, peeling-off entire hydrogen envelope. As consequence these two effects, maximum BH we expect from collapse rotating is only $\sim{}45$...
ABSTRACT Pair instability (PI) and pulsational PI prevent the formation of black holes (BHs) with mass ≳60 M⊙ from single star evolution. Here, we investigate possibility that BHs in gap form via stellar mergers multiple mergers, facilitated by dynamical encounters young clusters. We analyse 104 simulations, run direct N-body code nbody6++gpu coupled population synthesis mobse. find up to ∼6 per cent all simulated have gap, depending on progenitor’s metallicity. This channel is strongly...
Young star clusters are the most common birth-place of massive stars and dynamically active environments. Here, we study formation black holes (BHs) binary (BBHs) in young clusters, by means 6000 N-body simulations coupled with population synthesis. We probe three different stellar metallicities (Z=0.02, 0.002 0.0002) two initial density regimes (density at half-mass radius $\rho_{\rm h}\ge{}3.4\times10^4$ $\ge{1.5\times10^2}$ M$_\odot$ pc$^{-3}$ dense loose respectively). Metal-poor tend to...
Next generation ground-based gravitational-wave detectors will observe binary black hole (BBH) mergers up to redshift $z\gtrsim{}10$, probing the evolution of compact (CB) across cosmic time. Here, we present a new data-driven model estimate merger rate density (MRD) CBs, by coupling catalogs CB with observational constraints on star formation and metallicity Universe. We adopt derived from recent $N-$body population-synthesis simulations, describe MRD CBs formed in young clusters...
Using simulations performed with the population synthesis code MOBSE, we compute merger rate densities and detection rates of compact binary mergers formed in isolation for second- third-generation gravitational-wave detectors. We estimate how are affected by uncertainties on key stellar-physics parameters, namely common envelope evolution natal kicks. future upgrades will increase size available catalog events, discuss features density that become accessible
With the recent release of second gravitational-wave transient catalogue (GWTC-2), which introduced dozens new detections, we are at a turning point gravitational wave astronomy, as now able to directly infer constraints on astrophysical population compact objects. Here, tackle burning issue understanding origin binary black hole (BBH) mergers. To this effect, make use state-of-the-art synthesis and N-body simulations, represent two distinct formation channels: BBHs formed in field (isolated...
Ten binary black-hole mergers have already been detected during the first two observing runs of advanced LIGO and Virgo, many more are expected to be observed in near future. This opens possibility for gravitational-wave astronomy better constrain properties black hole binaries, not only as single sources, but a whole astrophysical population. In this paper, we address problem using measurements estimate proportion merging holes produced either via isolated binaries or evolving young star...
Hierarchical mergers are one of the distinctive signatures binary black hole (BBH) formation through dynamical evolution. Here, we present a fast semi-analytic approach to simulate hierarchical in nuclear star clusters (NSCs), globular (GCs) and young (YSCs). more common NSCs than they both GCs YSCs because different escape velocity. The mass distribution BBHs strongly depends on properties first-generation BBHs, such as their progenitor’s metallicity. In our fiducial model, form holes (BHs)...
In August 2017, Advanced Virgo joined LIGO for the end of O2 run, leading to first gravitational waves detections with three-detector network. This paper describes calibration and wave strain h(t) reconstruction during O2. The methods are same as ones developed initial detector have already been described in previous publications, this summarizes differences emphasis is put on estimating systematic uncertainties. Three versions signal computed an online version two post-run reprocessed...
The quantum radiation pressure and the shot noise in laser-interferometric gravitational wave detectors constitute a macroscopic manifestation of Heisenberg inequality. If can be easily observed, observation has been elusive, so far, due to technical competing with effects. Here, we discuss evidence Advanced Virgo detector. In our experiment, inject squeezed vacuum states light into interferometer order manipulate backaction on 42 kg mirrors observe corresponding driven displacement at...
Clustering measurements of Gravitational Wave (GW) mergers in Luminosity Distance Space can be used the future as a powerful tool for Cosmology. We consider tomographic Angular Power Spectrum both an Einstein Telescope-like detector network and some more advanced scenarios (more sources, better distance measurements, sky localization). produce Fisher forecasts cosmological (matter dark energy) merger bias parameters. Our fiducial model number distribution GW events is based on results from...
We report on a comprehensive all-sky search for periodic gravitational waves in the frequency band 100-1500 Hz and with time derivative range of $[-1.18, +1.00]\times 10^{-8}$ Hz/s. Such signal could be produced by nearby spinning slightly non-axisymmetric isolated neutron star our galaxy. This uses data from Initial LIGO sixth science run covers larger parameter space respect to any past search. A Loosely Coherent detection pipeline was applied follow up weak outliers both Gaussian (95%...
ABSTRACT We investigate the properties of host galaxies compact binary mergers across cosmic time, by means population-synthesis simulations combined with galaxy catalogues from eagle suite. analyse merger rate per neutron stars (BNSs), black hole–neutron star binaries (BHNSs), and holes (BBHs) redshift zero up to six. The strongly correlates stellar mass at any considered here. This correlation is significantly steeper for BNSs than both BHNSs BBHs. Moreover, we find that depends also on...
We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data the S6 LIGO science run. The was possible thanks to computing power provided by volunteers Einstein@Home distributed project. find no significant signal candidate and set most stringent upper limits date on amplitude wave signals target population. At frequency best strain sensitivity, between $170.5$ $171$ Hz we 90% confidence limit ${5.5}^{-25}$, while at high end our range,...
ABSTRACT GW190521 is the most massive binary black hole (BBH) merger observed to date, and its primary component lies in pair-instability (PI) mass gap. Here, we investigate formation of GW190521-like systems via three-body encounters young star clusters. We performed 2 × 105 simulations binary-single interactions between a BBH $\ge {60}\,$M⊙ (BH), including post-Newtonian terms up 2.5 order prescription for relativistic kicks. In our initial conditions, take into account possibility forming...