A5025502106- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Particle Detector Development and Performance
- CCD and CMOS Imaging Sensors
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Calibration and Measurement Techniques
- Methane Hydrates and Related Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Star Formation Studies
- Particle accelerators and beam dynamics
- History and Developments in Astronomy
Centre National de la Recherche Scientifique
2014-2024
Laboratoire d’Astrophysique de Marseille
2015-2024
Château Gombert
2014-2024
Aix-Marseille Université
2014-2024
Institut Pprime
2024
Centre National d'Études Spatiales
2022
Observatoire de la Côte d’Azur
2011
Lam Research (Austria)
2009-2011
Centre de Gestion Scientifique
2011
University of Oxford
2007
We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands, as part CFHT (CFHTLS). Follow-up spectroscopy was performed VLT, Gemini Keck telescopes confirm nature measure redshift. With this data...
We combine high redshift Type Ia supernovae from the first 3 years of Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample 472 SNe (123 low-$z$, 93 SDSS, 242 SNLS, and 14 {\it Hubble Space Telescope}). SN data alone require cosmic acceleration >99.9% confidence, including systematic effects. For dark energy equation state parameter (assumed constant out least $z=1.4$) in flat universe, we find $w =...
We present an empirical model of Type Ia supernovae spectro-photometric evolution with time. The is built using a large data set including light-curves and spectra both nearby distant supernovae, the latter being observed by SNLS collaboration. derive average spectral sequence their main variability components color variation law. allows us to measure distance moduli in range 2500-8000 A calculable uncertainties, those arising from features. Thanks use high-redshift SNe rest-frame UV energy...
We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z 1.1) discovered during the first three years Supernova Legacy Survey (SNLS). These events were detected their multi-colour light curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands. Follow-up spectroscopy was performed VLT, Gemini Keck telescopes to confirm nature measure redshifts....
We present observational constraints on the nature of dark energy using Supernova Legacy Survey three-year sample (SNLS3) Guy et al. and Conley use 472 Type Ia supernovae (SNe Ia) in this sample, accounting for recently discovered correlations between SN luminosity host galaxy properties, include effects all identified systematic uncertainties directly cosmological fits. Combining SNLS3 data with full WMAP7 power spectrum, Sloan Digital Sky luminous red a prior Hubble constant H0 from SHOES,...
(Abridged) Precision cosmology with Type Ia supernovae (SNe Ia) makes use of the fact that SN luminosities depend on their light-curve shapes and colours. Using Supernova Legacy Survey (SNLS) other data, we show there is an additional dependence global characteristics host galaxies: events same shape colour are, average, 0.08mag (~4.0sigma) brighter in massive galaxies (presumably metal-rich) low specific star-formation rates (sSFR). SNe a sSFR also have smaller slope ("beta") between...
(ABRIDGED) We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates depend on the mass mean star-formation (SFRs) of their host galaxies. Models where SN rate depends solely galaxy ruled out 99% confidence. Our analysis is based 100 spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events, all from Supernova Legacy Survey (SNLS) distributed over 0.2
We present SiFTO, a new empirical method for modeling Type Ia supernova (SN Ia) light curves by manipulating spectral template. make use of high-redshift SN data when training the model, allowing us to extend it bluer than rest-frame U. This increases utility our observations more available data. find that shape curve is described using stretch prescription, applying same at all wavelengths not an adequate description. SiFTO therefore uses generalization which applies different factors as...
We present new techniques for improving the efficiency of supernova (SN) classification at high redshift using 64 candidates observed Gemini North and South during first year Supernova Legacy Survey (SNLS). The SNLS is an ongoing 5 project with goal measuring equation state dark energy by discovering following over 700 high-redshift SNe Ia data from Canada-France-Hawaii Telescope Survey. achieve improvement in SN spectroscopic confirmation rate: 71% are now confirmed as Ia, compared to 54%...
We present two luminous UV/optical flares from the nuclei of apparently inactive early-type galaxies at z = 0.37 and 0.33 that have radiative properties a flare tidal disruption star. In this paper we report second candidate event discovery in UV by GALEX Deep Imaging Survey simultaneous optical light curves CFHTLS for both flares. The first few months are well fitted with canonical t−5/3 power-law decay predicted emission fallback debris tidally disrupted Chandra ACIS X-ray observations...
We present optical, X-ray and gamma-ray observations of GRB 111209A, observed at a redshift z = 0.677. show that this event was active in its prompt phase for about 25000 s, making it the longest burst ever observed. This rare could have been detected up to ∼ 1.4 gamma-rays. Compared other long bursts (GRBs), 111209A is clear outlier energy-fluence duration plane. The high-energy emission shows no sign strong blackbody component, signature tidal disruption event, or supernova shock breakout....
In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on flux have obtained. Assuming an E−2ν spectrum, these are at 1–10 ×10−8 GeV cm−2 s−1 declinations ranging −90° 40°. Limits specific models RX J1713.7−3946 Vela X, which include information source morphology also given.
A search for muon neutrinos originating from dark matter annihilations in the Sun is performed using data recorded by ANTARES neutrino telescope 2007 to 2012. In order obtain best possible sensitivities signals, an optimisation of event selection criteria taking into account background atmospheric muons, and energy spectra expected signals. No significant excess over observed $90\%$ C.L. upper limits on flux, spin--dependent spin--independent WIMP-nucleon cross--sections are derived WIMP...
A search for cosmic neutrino sources using six years of data collected by the ANTARES telescope has been performed. Clusters muon neutrinos over expected atmospheric background have looked for. No clear signal found. The most signal-like accumulation events is located at equatorial coordinates R.A. = −468 and decl. −649 corresponds to a 2.2σ fluctuation. In addition, upper limits on flux normalization an E−2 energy spectrum set 50 pre-selected astrophysical objects. Finally, motivated seven...
THESEUS, one of the two space mission concepts being studied by ESA as candidates for next M5 within its Comsic Vision programme, aims at fully exploiting Gamma-Ray Bursts (GRB) to solve key questions about early Universe, well becoming a cornerstone multi-messenger and time-domain astrophysics. By investigating first billion years Universe through high-redshift GRBs, THESEUS will shed light on main open issues in modern cosmology, such population primordial low mass luminosity galaxies,...
Interactions of cosmic ray protons, atomic nuclei, and electrons in the interstellar medium inner part Milky Way produce a $\gamma$-ray flux from Galactic Ridge. If emission is dominated by proton nuclei interactions, neutrino comparable to expected same sky region. Data collected ANTARES telescope are used constrain Ridge 1-100 TeV energy range. Neutrino events reconstructed both as tracks showers considered analysis selection optimized for search an excess region $|l| < 30\deg$, $|b|...
The NOMAD experiment is a short base-line search for νμ − ντ oscillations in the CERN neutrino beam. ντ's are searched through their charged current interactions followed by observation of resulting τ− its electronic, muonic or hadronic decays. These decays recognized using kinematical criteria necessitating use light target which enables reconstruction individual particles produced interactions. This paper describes various components detector: and muon drift chambers, electromagnetic...
A supermassive black hole in the nucleus of a galaxy will be revealed when star passes close enough to torn apart by tidal forces and flare radiation is emitted stream stellar debris that plunges into hole. Since common active galactic nuclei have accreting holes can also produce flares, convincing demonstration disruption has occurred generally begins with ``normal'' no evidence prior nuclear activity. Here we report luminous UV from an elliptical at z = 0.37 Groth field GALEX Deep Imaging...