D. Fouchez
A5044982703- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Astro and Planetary Science
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- CCD and CMOS Imaging Sensors
- Computational Physics and Python Applications
- Advanced Vision and Imaging
- Adaptive optics and wavefront sensing
- Impact of Light on Environment and Health
- Remote Sensing in Agriculture
Centre de physique des particules de Marseille
2015-2025
Centre National de la Recherche Scientifique
2014-2023
Aix-Marseille Université
2014-2023
Institut National de Physique Nucléaire et de Physique des Particules
2006-2020
Max Planck Institute for Astronomy
2008
Laboratoire de Physique Nucléaire et de Hautes Énergies
2008
Sorbonne Université
2008
Université Paris Cité
2008
University of Oxford
2008
University of Victoria
2008
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...
Aims. We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons (0.05 <z< 0.4), years (0.2 1), it totals 740 spectroscopically confirmed supernovae with high-quality light curves.
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
Previously we used the Nearby Supernova Factory sample to show that Type Ia supernovae (SNe Ia) having locally star-forming environments are dimmer than SNe passive environments. Here use Constitution together with host galaxy data from GALEX independently confirm result. The effect is seen using both SALT2 and MLCS2k2 lightcurve fitting standardization methods, brightness differences of 0.094 ± 0.037 mag for 0.155 0.041 RV = 2.5. When combined our previous measurement 0.025 SALT2. If ratio...
As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization Type Ia supernovae (SNIa) cosmology, we have statistically classified a large sample nearby SNeIa into those located predominantly younger or older environments. This classification is based on specific star formation rate measured within projected distance 1kpc from each SN location (LsSFR). important refinement compared using local directly as it provides normalization relative...
Context. As type Ia supernova cosmology transitions from a statistics-dominated to systematics-dominated era, it is crucial understand the remaining unexplained uncertainties that affect their luminosity, such as those stemming astrophysical biases. Type supernovae are standardisable candles whose absolute magnitude reaches scatter of typically 0.15 mag when empirical correlations with light-curve stretch and colour environmental properties accounted for. Aims. We investigate dependence...
Context. Type Ia supernova (SN Ia) cosmology studies will soon be dominated by systematic, uncertainties, rather than statistical ones. Thus, it is crucial to understand the unknown phenomena potentially affecting their luminosity that may remain, such as astrophysical biases. For accurate application in studies, SN magnitudes need standardised; namely, they must corrected for correlation with light-curve width and colour. Aims. Here, we investigate how standardisation procedure used reduce...
Context. The unprecedented statistics of detected Type Ia supernovae (SNe Ia) brought by the Zwicky Transient Facility (ZTF) enable us to probe impact large-scale structure (LSS) on properties these objects. Aims. goal this paper is explore possible under-dense part LSS intrinsic SALT2 light-curve SNe and uncover biases in SN analyses. Methods. With a volume-limited selection ZTF-Cosmo-DR2 overlapping with SDSS-DR7 survey footprint, we investigated distribution their regard voids galaxy...
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...
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations used constrain explosion scenarios. We base our discussion on three-dimensional simulations a delayed detonation Chandrasekhar-mass white dwarf violent merger two dwarfs-realizations models appropriate most...
We present 32 epochs of optical (3300-9700 \AA) spectrophotometric observations the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in galaxy M101, extending from -15 to +97 d with respect B-band maximum, obtained by Nearby Supernova Factory collaboration. is closest (\mu = 29.04) and brightest (Bmax 9.94 mag) observed since advent modern large scale programs for intensive periodic followup supernovae. Both synthetic light curve measurements spectral feature analysis...
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 the first high-redshift Hubble diagram for Type II-P supernovae (SNe II-P) based upon five events at redshift up to z~0.3. This was constructed using photometry from Canada-France-Hawaii Telescope Supernova Legacy Survey and absorption line spectroscopy Keck observatory. The method used measure distances these is on recent work by Hamuy & Pinto (2002) exploits a correlation between absolute brightness of SNe expansion velocities derived minimum Fe II 516.9 nm P-Cygni feature...
We use three years of data from the Supernova Legacy Survey (SNLS) to study general properties core-collapse and type Ia supernovae. This is first such using "rolling search" technique which guarantees well-sampled SNLS light curves good efficiency for supernovae brighter than $i^\prime\sim24$. Using host photometric redshifts, we measure supernova absolute magnitude distribution down luminosities $4.5 {\rm mag}$ fainter normal SNIa. spectroscopy light-curve fitting discriminate against...
Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting catastrophic “core-collapse” supernova. Such events are usually only detected at least few days after star has exploded. Observations supernova SNLS-04D2dc with Galaxy Evolution Explorer space telescope reveal radiative precursor from shock before reached surface and show initial expansion beginning explosion. Theoretical models ultraviolet light curve confirm that progenitor was red...
We analyze the mean rest-frame ultraviolet (UV) spectrum of Type Ia Supernovae (SNe Ia) and its dispersion using high signal-to-noise Keck-I/LRIS-B spectroscopy for a sample 36 events at intermediate redshift (z=0.5) discovered by Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). introduce new method removing host galaxy contamination in our spectra, exploiting comprehensive photometric coverage SNLS SNe their galaxies, thereby providing first quantitative view UV spectral...
We present the photometric calibration of Supernova Legacy Survey (SNLS) fields. The SNLS aims at measuring distances to SNe Ia (0.3<z<1) using MegaCam, 1 deg^2 imager on Canada-France-Hawaii Telescope (CFHT). uncertainty affecting survey dominates systematic key measurement survey, namely dark energy equation state. requires obtaining a uniform response across imager, calibrating science field stars in each band (SDSS-like ugriz bands) with respect standards known flux same bands, and...
Timmes, Brown & Truran found that metallicity variations could theoretically account for a 25% variation in the mass of 56Ni synthesized Type Ia supernovae (SNe Ia), and thus large fraction scatter observed SN luminosities. Higher-metallicity progenitors are more neutron-rich, producing stable burning products relative to radioactive 56Ni. We develop new method estimating bolometric luminosity yield SNe use it test theory with data from Supernova Legacy Survey. find average does drop high...