Pierre-and-Marie-Curie University

About: Pierre-and-Marie-Curie University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 34448 authors who have published 56139 publications receiving 2392398 citations.

The sloan lens acs survey. x. stellar, dynamical, and total mass correlations of massive early-type galaxies

Abstract: We use stellar masses, surface photometry, strong-lensing masses, and stellar velocity dispersions (σ e/2) to investigate empirical correlations for the definitive sample of 73 early-type galaxies (ETGs) that are strong gravitational lenses from the SLACS survey. The traditional correlations (fundamental plane (FP) and its projections) are consistent with those found for non-lens galaxies, supporting the thesis that SLACS lens galaxies are representative of massive ETGs (dimensional mass M dim = 1011-1012 M ☉). The addition of high-precision strong-lensing estimates of the total mass allows us to gain further insights into their internal structure: (1) the average slope of the total mass-density profile ( ) is γ' = 2.078 ± 0.027 with an intrinsic scatter of 0.16 ± 0.02; (2) γ' correlates with effective radius (re ) and central mass density, in the sense that denser galaxies have steeper profiles; (3) the dark matter (DM) fraction within re /2 is a monotonically increasing function of galaxy mass and size (due to a mass-dependent central cold DM distribution or due to baryonic DM—stellar remnants or low-mass stars—if the initial mass function is non-universal and its normalization increases with mass); (4) the dimensional mass M dim ≡ 5re σ2 e/2/G is proportional to the total (lensing) mass M , and both increase more rapidly than stellar mass M * (M ); (5) the mass plane (MP), obtained by replacing surface brightness with surface mass density in the FP, is found to be tighter and closer to the virial relation than the FP and the M*P, indicating that the scatter of those relations is dominated by stellar population effects; (6) we construct the fundamental hyper-plane by adding stellar masses to the MP and find the M * coefficient to be consistent with zero and no residual intrinsic scatter. Our results demonstrate that the dynamical structure of ETGs is not scale invariant and that it is fully specified by M , re , and σ e/2. Although the basic trends can be explained qualitatively in terms of varying star formation efficiency as a function of halo mass and as the result of dry and wet mergers, reproducing quantitatively the observed correlations and their tightness may be a significant challenge for galaxy formation models.

Impacts of ocean acidification on marine shelled molluscs

Abstract: Over the next century, elevated quantities of atmospheric CO2 are expected to penetrate into the oceans, causing a reduction in pH (-0.3/-0.4 pH unit in the surface ocean) and in the concentration of carbonate ions (so-called ocean acidification). Of growing concern are the impacts that this will have on marine and estuarine organisms and ecosystems. Marine shelled molluscs, which colonized a large latitudinal gradient and can be found from intertidal to deep-sea habitats, are economically and ecologically important species providing essential

Measurement of the Depth of Maximum of Extensive Air Showers above 10(18) eV

Abstract: We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/- 0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

A family of low and high copy replicative, integrative and single‐stranded S. cerevisiae/E. coli shuttle vectors

Abstract: We describe a set of replicative, integrative and single-stranded shuttle vectors constructed from the pUC19 plasmid that we use routinely in our experiments. They bear a yeast selectable marker: URA3, TRP1 or LEU2. Replicative vectors carrying different yeast replication origins have been constructed in order to have plasmids based on the same construction with a high or low copy number per cell and with different mitotic stabilities. All the vectors are small in size, provide a high yield in Escherichia coli and efficiently transform Saccharomyces cerevisiae. These plasmids have many of the unique sites of the pUC19 multicloning region and many of them allow for the screening of plasmids with an insert by alpha-complementation. The nucleotide sequence of each of them is completely known.