The Clustering of Intergalactic Metals

We measure the spatial clustering of metals in the intergalactic medium from z = 1.7 to 3.0, as traced by 643 CIV and 104 SiIV N >= 10^12 cm^-2 absorption systems in 19 high signal-to-noise (40-80) and high resolution (R = 45000) quasar spectra. The number densities and two-point correlation functions of both these species are largely constant with redshift, suggesting the bulk of metal ejection occurred at z >= 3. However, at z <= 1.9 some additional signature appears in the CIV correlation function at 500 km/s, associated with four strong and peculiar systems. At all redshifts, the CIV and SiIV correlation functions exhibit a steep rise at large separations and a flatter profile at small separations, with an elbow occurring at ~150 km/s. We show that these properties are consistent with metals confined within bubbles with a typical radius R_s about sources of mass >= M_s, and use numerical simulations to derive best-fit values of R_s ~ 2 comoving Mpc and M_s ~ 5x10^11 solar masses at z = 3. This does not exclude that metals could have been produced at higher redshifts in smaller, but equally rare, objects. At the level of detection of this survey, IGM enrichment is likely to be incomplete and inhomogeneous, with a filling factor ~ 10%.Comment: 5 pages, 3 figures, ApJ Letters accepte

Sciences, sociétés, pouvoirs : approches historiques

Dominique Pestre, directeur d’études Introduction à l’histoire des sciences (avec Laurent Pinon, maître de conférences à l’ENS) Le séminaire a été donné conjointement aux étudiants de la filière « Étude des sciences et des techniques » des DEA de l’EHESS et à ceux des magistères de l’ENS-Ulm. Il s’agit d’un enseignement systématique d’introduction au domaine, enseignement rendu nécessaire par le fait que n’existe aucun cursus de second cycle en histoire des sciences et qu’un nombre notable de..

A Middleware for Control Applications

This paper proposes an original Object Oriented architecture and an associated framework to set-up easily and safely control software. To improve the design process of such a software several propositions are given: a multi-application support, a layered model, a semantic variable abstraction, a synchronising mechanism and a factoring process. The example illustrates how the architecture can be used to build complex applications. A two tanks plant is simulated and a supervised controlled application illustrates a multi-worlds system with concurrent control and supervision algorithms

Publier le métier, quelles perspectives ?

L\u27enjeu de cette journée est de réfléchir aux mutations actuelles de la production et de la diffusion de ressources à destination des communautés professionnelles des bibliothèques : - Édition de manuels et ressources en ligne - Recherches et réflexions professionnelles, ouvertes à de nouveaux métiers - Éditions homothétiques ou "pure player" - Modes de production spécifiques : ressources continues, blogs, carnets de recherche, tutoriels et manuels en ligne, etc. Crise du modèle actuel ? Évolution des besoins, des pratiques de lecture, des pratiques d’écriture ? … Sans doute un peu tout à la fois. Alors, comment penser l\u27avenir d\u27une littérature professionnelle utile

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Varron, Res Rusticae, Livre II. Texte établi, traduit et commenté

Petitjean Dominique. Varron, Res Rusticae, Livre II. Texte établi, traduit et commenté. In: École pratique des hautes études. 4e section, Sciences historiques et philologiques. Annuaire 1972-1973. 1973. pp. 823-826

AN ABINITIO STUDY OF THE ISOMERIZATION AND FRAGMENTATION OF CHO2+ IONS - AN EXAMPLE OF SPIN-CONTROLLED REACTIONS

peer reviewed[CHO2+] ions exist in two isomeric forms, a quasi-linear carboxylic structure, OCOH+ (I), and a formate structure, O(CH)O+ (II). The latter is known to isomerise into the former with a low rate constant (about 105 s−1). Configuration interaction ab initio calculations reveal that the ion can exist in three low-lying electronic states of different multiplicity and symmetry species, a singlet (Image 1A′) and two triplets (ã3A′ and Image 3A′'). The potential energy surfaces cross so that the nature of the lowest state varies as a function of the nuclear geometry. The singlet surface (Image 1A′) has its deepest minimum for structure I and a subsidiary minimum for structure II. The situation is reversed for the ã3A′ state which has its deepest minimum for structure II and which exhibits a shallow minimum for structure I. Thus, at low energies, the carboxylic and formate ions are respectively in a singlet and in a triplet state. These ions lose an oxygen atom on a microsecond time scale by a composite mechanism which is subject to a large isotope effect. One of the components of the metastable peak corresponds to reaction OCOH+(1A') -> O(CH)O+ (3A') -> HCO+ + O giving rise to a small kinetic energy release. The second component is due to a spin-orbit controlled direct predissociation process, viz. OCOH+ (1A') -> OCOH+ (3A') -> HOC+ + O. The probability of surface hopping varies as a function of the internal energy between 0 and a maximum value of ca. 0.008. The corresponding kinetic energy release is expected to be larger for the deuterated than for the hydrogenated compound. Thus, the two components are resolved in the deuterated compound, but hardly distinguishable in the hydrogenated species

LESIONS FIBRO-INFLAMMATOIRES IDIOPATHIQUES DE LA REGION PANCREATICO-BILIAIRE A PRESENTATION PSEUDOTUMORALE (ETUDE ANATOMOCLINIQUE, IMMUNOHISTOCHIMIQUE ET PAR HYBRIDATION IN SITU DE TROIS CAS AVEC REVUE DE LA LITTERATURE)

PARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF