A5031194869- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- Advanced optical system design
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- CCD and CMOS Imaging Sensors
- Optical Coatings and Gratings
- Calibration and Measurement Techniques
- Neutrino Physics Research
- Advanced Measurement and Metrology Techniques
- Optical Polarization and Ellipsometry
- Optical Systems and Laser Technology
- Astro and Planetary Science
- Optical measurement and interference techniques
- Galaxies: Formation, Evolution, Phenomena
- Advanced Semiconductor Detectors and Materials
- Pulsars and Gravitational Waves Research
- Photocathodes and Microchannel Plates
- Infrared Target Detection Methodologies
- Astrophysical Phenomena and Observations
- Image Processing Techniques and Applications
- solar cell performance optimization
- Advanced MEMS and NEMS Technologies
Centre National de la Recherche Scientifique
2017-2025
Aix-Marseille Université
2017-2025
Château Gombert
2019-2024
Laboratoire d’Astrophysique de Marseille
2017-2024
Centre National d'Études Spatiales
2022
Humboldt-Universität zu Berlin
2014-2020
University of Bonn
2013-2018
LAM Foundation
2018
Bellingham Technical College
2018
Centre National pour la Recherche Scientifique et Technique (CNRST)
2018
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...
(Abridged) We study the host galaxy regions in close proximity to Type Ia supernovae (SNe Ia) analyze relations between properties of SN events and environments most similar where their progenitors formed. focus on local H\alpha\ emission as an indicator young environments. The Nearby Supernova Factory has obtained flux-calibrated spectral timeseries for SNe using integral field spectroscopy, allowing simultaneous measurement its immediate vicinity. For 89 we measure tracing ongoing star...
Type Ia supernova cosmology depends on the ability to fit and standardize observations of magnitudes with an empirical model. We present here a series new models Supernova spectral time that capture greater amount diversity than possible are currently customary. These entitled SuperNova Empirical MOdels (\textsc{SNEMO}\footnote{https://snfactory.lbl.gov/snemo}). The constructed using spectrophotometric from $172$ individual supernovae Nearby Factory, comprising more $2000$ spectra. Using...
Minimizing system size and weight without sacrificing the desired imaging performance is a crucial challenging goal in design of off-axis optical systems. In this paper, we propose concept that combines freeform mirror detector to achieve more compact Initially, by applying nodal aberration theory, optimal focal surface shape for systems demonstrated be an paraboloid or even surface, rather than commonly assumed spherical shape. Subsequently, show ability reduce volume through example fast...
We introduce a method for identifying "twin" Type Ia supernovae, and using them to improve distance measurements. This novel approach supernova standardization is made possible by spectrophotometric time series observations from the Nearby Supernova Factory (SNfactory). begin with well-measured set of find pairs whose spectra match well across entire optical window, then test whether this leads smaller dispersion in their absolute brightnesses. analysis completed blinded fashion, ensuring...
We develop a new framework for use in exploring Type Ia Supernova (SN Ia) spectra. Combining Principal Component Analysis (PCA) and Partial Least Square analysis (PLS) we are able to establish correlations between the Components (PCs) spectroscopic/photometric SNe features. The technique was applied ~120 supernova ~800 spectra from Nearby Factory. ability of PCA group together with similar spectral features, already explored previous studies, is greatly enhanced by two important...
We present the design of an all-reflective, bifolded Schmidt telescope aimed at surveys extended astronomical objects with extremely low surface brightness. The leads to a high image quality without any diffracting spider, large aperture and field view (FoV), small central obstruction that barely alters point spread function (PSF). As example, we high-quality, 36 cm diameter, fast (f/2.5) working in visible FoV (1.6°×2.6°). can operate curved detector (or flat flattener) set filters....
Correction of Type Ia Supernova brightnesses for extinction by dust has proven to be a vexing problem. Here we study the foreground highly reddened SN 2012cu, which is projected onto lane in galaxy NGC 4772. The analysis based on multi-epoch, spectrophotometric observations spanning 3,300 - 9,200 {\AA}, obtained Nearby Factory. Phase-matched comparison spectroscopically twinned 2012cu and 2011fe across 10 epochs results best-fit color excess (E(B-V), RMS) = (1.00, 0.03) total-to-selective...
Type Ia Supernovae (SNe Ia) are widely used to measure the expansion of Universe. Improving distance measurements SNe is one technique better constrain acceleration and determine its physical nature. This document develops a new spectral energy distribution (SED) model, called SUpernova Generator And Reconstructor (SUGAR), which improves description Ia, consequently could improve measurements. model constructed from properties spectrophotometric data The Nearby Supernova Factory...
Context . Transient sky astronomy is entering a new era with the advent of Space Variable Objects Monitor mission (SVOM), successfully launched on 22 June 2024. The primary goal SVOM to monitor hard X-ray searching for gamma-ray bursts (GRBs). On top its on-board follow-up capabilities, will be backed by ground segment composed several facilities, including near-infrared (NIR) imager CAGIRE. Mounted robotic telescope COLIBRI, it unique instrument capable performing fast GRB afterglows in J...
Over the recent years, a huge interest has grown for curved electronics, particularly opto-electronics systems. Curved sensors help correction of off-axis aberrations, such as Petzval Field Curvature, astigmatism, and bring significant optical size benefits imaging In this paper, we first describe advantages sensor associated packaging process applied on 1/1.8'' format 1.3Mpx global shutter CMOS (Teledyne EV76C560) into its standard ceramic package with spherical radius curvature Rc=65mm...
Curved sensors are a suitable technological solution to enhance the vast majority of optical systems. In this work, we show entire process create curved sensor-based systems and possibilities they offer. This paper defines boundaries reachable curvatures for full range monolithic sensors. We discuss how focal plane shape is related imaged scenes parameters. Two camera prototypes designed, realized, tested, demonstrating new compact architecture 40 deg objective as well wide-field fisheye...
We consider using toroidal curved detectors to improve the performance of imaging optical systems. demonstrate that some systems have an anamorphic field curvature. unobscured reimaging three-mirror anastigmat as example (f'=960 mm, F/5.3, ωx×ωy=4°×4°). By assuming image is focused on a detector surface and performing reoptimization, it becomes possible obtain notable gain in quality-up 40% terms spot root mean square radius. Through analytic computations finite-element analysis, we this...
Context. Observations of type Ia supernovae (SNe Ia) can be used to derive accurate cosmological distances through empirical standardization techniques. Despite this success neither the progenitors SNe nor explosion process are fully understood. The U -band region has been less well observed for nearby SNe, due technical challenges, but is most readily accessible band high-redshift SNe. Aims. Using spectrophotometry from Nearby Supernova Factory, we study origin and extent spectroscopic...
Kim et al. (2013) [K13] introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization curves and Hubble residuals, based on photometry synthesized Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 residual step host mass is $0.013\pm 0.031$ mag supernova subsample data coverage corresponding to training; at $\ll 1σ$,...
3D printing, also called additive manufacturing, offers a new vision for optical fabrication in term of achievable quality and reduction weight cost. In this paper we describe two different ways to use technique the process. The first method makes printing warping harnesses stress polishing, apply that WFIRST coronagraph off axis parabolas. second considers proof concept lightweight X-Ray mirrors, targeting next generation X-rays telescopes. Stress polishing is well suited high parabolas...
The present paper describes the current baseline optical design of POLLUX, a high-resolution spectropolarimeter for future LUVOIR mission. instrument will operate in ultraviolet (UV) domain from 90 to 390 nm both spectropolarimetric and pure spectroscopic modes. working range is split between 3 channels – far (90-124.5 nm), medium (118.5-195 nm) near (195-390 UV. Each composed polarimeter followed by an echelle spectrograph consisting classical off-axis paraboloid collimator, grating with...
Due to the increasing dimension, complexity, and cost of future astronomical surveys, new technologies enabling more compact simpler systems are required. The development curved detectors allows enhancement performances optical system used (telescope or instrument), while keeping compact. We describe here a set five complementary metal-oxide semiconductor (CMOS) developed within collaboration between CEA-LETI CNRS-LAM. These fully functional 20 Mpix (CMOSIS CMV20000) have been different...
Over the recent years, a huge interest has grown for curved electronics, particularly opto-electronics systems. Indeed, sensors help correction of off-axis aberrations, such as Petzval Field Curvature and astigmatism. In this paper, we describe benefits curvature tunable on an existing fish-eye lens. We proposed new design architecture, compact with high resolution, developed specifically image sensor. discuss about aberrations effect higher sensor third order aberrations. Besides, show...
Abstract The Nearby Supernova Factory presents an interim data release of spectrophotometric timeseries 210 SNe Ia. Two slightly different versions the are included, corresponding to training sets used for SNEMO and SUGAR Type Ia models. has been shifted restframe is blinded with respect cosmology.
Type Ia Supernovae (SNe Ia) are widely used to measure the expansion of Universe. To perform such measurements luminosity and cosmological redshift ($z$) SNe have be determined. The uncertainty on $z$ includes an unknown peculiar velocity, which can very large for in virialized cores massive clusters. We determine exploded galaxy then study how correction velocities host galaxies inside clusters improves Hubble residuals. Using 145 from Nearby Supernova Factory we found 11 candidates...
ABSTRACT In spite of major advances in both ground- and space-based instrumentation, the ultralow surface brightness Universe (ULSB) still remains a largely unexplored volume observational parameter space. ULSB observations provide unique constraints on wide variety objects, from Zodiacal light all way to optical cosmological background radiation, through dust cirri, mass-loss shells giant stars, LSB galaxies intracluster light. These levels (>28–29 mag arcsec−2) are observed by...