Spinor condensates and light scattering from Bose-Einstein condensates

These notes discuss two aspects of the physics of atomic Bose-Einstein condensates: optical properties and spinor condensates. The first topic includes light scattering experiments which probe the excitations of a condensate in both the free-particle and phonon regime. At higher light intensity, a new form of superradiance and phase-coherent matter wave amplification were observed. We also discuss properties of spinor condensates and describe studies of ground--state spin domain structures and dynamical studies which revealed metastable excited states and quantum tunneling.Comment: 58 pages, 33 figures, to appear in Proceedings of Les Houches 1999 Summer School, Session LXXI

Euclid preparation: XVII. Cosmic dawn survey: Spitzer space telescope observations of the Euclid deep fields and calibration fields

Galaxie

Euclid preparation. XV. Forecasting cosmological constraints for the Euclid and CMB joint analysis

Galaxie

Euclid preparation: XVIII. The NISP photometric system

Galaxie

Update on HI data collection from GBT, Parkes and Arecibo telescopes for the Cosmic Flows project

accepted for MNRASInternational audienceCosmic Flows is an international multi-element project with the goal to map motions of galaxies in the Local Universe. Kinematic information from observations in the radio HI line and photometry at optical or near-infrared bands are acquired to derive the large majority of distances that are obtained through the luminosity-linewidth or Tully-Fisher relation. This paper gathers additional observational radio data, frequently unpublished, retrieved from the archives of Green Bank, Parkes and Arecibo telescopes. Extracted HI profiles are consistently processed to produce linewidth measurements. Our current "All-Digital HI Catalog" contains a total of 20,343 HI spectra for 17,738 galaxies with 14,802 galaxies with accurate linewidth measurement useful for Tully-Fisher galaxy distances. This addition of 4,117 new measurements represents an augmentation of 34\% compared to our last release

An estimation of the local growth rate from Cosmicflows peculiar velocities

International audienceThis article explores three usual estimators, noted as v_12 of the pairwise velocity, ψ_1 and ψ_2 of the observed two-point galaxy peculiar velocity correlation functions. These estimators are tested on mock samples of Cosmicflows-3 data set (Tully, Courtois & Sorce), derived from a numerical cosmological simulation, and also on a number of constrained realizations of this data set. Observational measurements errors and cosmic variance are taken into consideration in the study. The result is a local measurement of fσ_8 = 0.43(± 0.03)_obs(± 0.11)_cosmic out to z = 0.05, in support of a ΛCDM cosmology

Cosmography of the Local Universe

movie that can be viewed and downloaded at : http://irfu.cea.fr/cosmography or http://vimeo.com/pomarede/cosmography -- In Press for Astronomical JournalThe large scale structure of the universe is a complex web of clusters, filaments, and voids. Its properties are informed by galaxy redshift surveys and measurements of peculiar velocities. Wiener Filter reconstructions recover three-dimensional velocity and total density fields. The richness of the elements of our neighborhood are revealed with sophisticated visualization tools. A key component of this paper is an accompanying movie that can be viewed and downloaded at : http://irfu.cea.fr/cosmography or http://vimeo.com/pomarede/cosmography .The ability to translate and zoom helps the viewer follow structures in three dimensions and grasp the relationships between features on different scales while retaining a sense of orientation. The ability to dissolve between scenes provides a technique for comparing different information, for example, the observed distribution of galaxies, smoothed representations of the distribution accounting for selection effects, observed peculiar velocities, smoothed and modeled representations of those velocities, and inferred underlying density fields. The agreement between the large scale structure seen in redshift surveys and that inferred from reconstructions based on the radial peculiar velocities of galaxies strongly supports the standard model of cosmology where structure forms from gravitational instabilities and galaxies form at the bottom of potential wells

Cosmic flows: University of Hawaii 2.2-m I-band photometry

Within the 'Cosmic Flows' project, I-band photometry of 524 relatively nearby galaxies has been carried out over the course of several years with the University of Hawaii 2.2-m telescope and a camera with a 7.5-arcmin field of view. The primary scientific goal was to provide global magnitudes and inclinations for galaxies for the purpose of measuring distances through the correlation between galaxy luminosities and rotation rates. The 1σ accuracy on a total magnitude is 0.08 mag. The observations typically extend to 7-8 exponential disc scalelengths, so the data are useful for studies of the structural properties of galaxies

MoLUSC: A MOck Local Universe Survey Constructor

submitted to ApJThis paper presents MoLUSC, a new method for generating mock galaxy catalogs from a large scale ($\approx 1000^3$ Mpc$^3$) dark matter simulation, that requires only modest CPU time and memory allocation. The method uses a small-scale ($\approx 256^3$ Mpc$^3$) dark matter simulation on which the \galics semi-analytic code has been run in order to define the transformation from dark matter density to galaxy density transformation using a probabilistic treatment. MoLUSC is then applied to a large-scale dark matter simulation in order to produce a realistic distribution of galaxies and their associated spectra. This permits the fast generation of large-scale mock surveys using relatively low-resolution simulations. We describe various tests which have been conducted to validate the method, and demonstrate a first application to generate a mock Sloan Digital Sky Survey redshift survey

Reconstructing cosmological initial conditions from galaxy peculiar velocities. III. Constrained simulations

Accepted for MNRAS, 2012 december 12In previous works we proposed the Reverse Zeldovich Approximation (RZA) method, which can be used to estimate the cosmological initial conditions underlying the galaxy distribution in the Local Universe using peculiar velocity data. In this paper, we apply the technique to run constrained cosmological simulations from the RZA-reconstructed initial conditions, designed to reproduce the large-scale structure of the Local Universe. We test the method with mock peculiar velocity catalogues extracted from a reference simulation. We first reconstruct the initial conditions of this reference simulation using the mock data, and then run the reconstructed initial conditions forward in time until z=0. We compare the resulting constrained simulations with the original simulation at z=0 to test the accuracy of this method. We also compare them with constrained simulations run from the mock data without the addition of RZA, i.e. using only the currently established constrained realizations (CR) method. Our re-simulations are able to correctly recover the evolution of the large-scale structure underlying the data. The results show that the addition of RZA to the CR method significantly improves both the reconstruction of the initial conditions and the accuracy of the obtained constrained resimulations. Haloes from the original simulation are recovered in the re-simulations with an average accuracy of about 2 Mpc/h on their position and a factor of 2 in mass, down to haloes with a mass of approx 10^14 M_odot/h. In comparison, without RZA the re-simulations recover only the most massive haloes with masses of about 5x10^14 M_odot/h and higher, and with a systematic shift on their position of about approx 10 Mpc/h due to the cosmic displacement field. We show that with the additional Lagrangian reconstruction step introduced by the RZA, this shift can be removed