We present a fully consistent catalog of local and global properties of host galaxies of 882 Type Ia supernovæ (SNIa) that were selected based on their light-curve properties, spanning the redshift ...range 0.01 < z < 1. This catalog corresponds to a preliminary version of the compilation sample and includes Supernova Legacy Survey (SNLS) 5-year data, Sloan Digital Sky Survey (SDSS), and low-redshift surveys. We measured low- and moderate-redshift host galaxy photometry in SDSS stacked and single-epoch images and used spectral energy distribution fitting techniques to derive host properties such as stellar mass and U − V rest-frame colors; the latter are an indicator of the luminosity-weighted age of the stellar population in a galaxy. We combined these results with high-redshift host photometry from the SNLS survey and thus obtained a consistent catalog of host stellar masses and colors across a wide redshift range. We also estimated the local observed fluxes at the supernova location within a proper distance radius of 3 kpc, corresponding to the SNLS imaging resolution, and transposed them into local U − V rest-frame colors. This is the first time that local environments surrounding SNIa have been measured at redshifts spanning the entire Hubble diagram. Selecting SNIa based on host photometry quality, we then performed cosmological fits using local color as a third standardization variable, for which we split the sample at the median value. We find a local color step significance of − 0.091 ± 0.013 mag (7σ), which effect is as significant as the maximum mass step effect. This indicates that the remaining luminosity variations in SNIa samples can be reduced with a third standardization variable that takes the environment into account. Correcting for the maximum mass step correction of − 0.094 ± 0.013 mag, we find a local color effect of − 0.057 ± 0.012 mag (5σ), which shows that additional information is provided by the close environment of SNIa. Departures from the initial choices were investigated and showed that the local color effect is still present, although less pronounced. We discuss the possible implications for cosmology and find that using the local color in place of the stellar mass results in a change in the measured value of the dark energy equation-of-state parameter of 0.6%. Standardization using local U − V color in addition to stretch and color reduces the total dispersion in the Hubble diagram from 0.15 to 0.14 mag. This will be of tremendous importance for the forthcoming SNIa surveys, and in particular for the Large Synoptic Survey Telescope (LSST), for which uncertainties on the dark energy equation of state will be comparable to the effects reported here.
Aims. The statistical distribution of galaxies is a powerful probe to constrain cosmological models and gravity. In particular, the matter power spectrum P(k) provides information about the ...cosmological distance evolution and the galaxy clustering. However the building of P(k) from galaxy catalogs requires a cosmological model to convert angles on the sky and redshifts into distances, which leads to difficulties when comparing data with predicted P(k) from other cosmological models, and for photometric surveys like the Large Synoptic Survey Telescope (LSST). The angular power spectrum Cℓ(z1,z2) between two bins located at redshift z1 and z2 contains the same information as the matter power spectrum, and is free from any cosmological assumption, but the prediction of Cℓ(z1,z2) from P(k) is a costly computation when performed precisely. Methods. The Angpow software aims at quickly and accurately computing the auto (z1 = z2) and cross (z1 ≠ z2) angular power spectra between redshift bins. We describe the developed algorithm based on developments on the Chebyshev polynomial basis and on the Clenshaw-Curtis quadrature method. We validate the results with other codes, and benchmark the performance. Results. Angpow is flexible and can handle any user-defined power spectra, transfer functions, and redshift selection windows. The code is fast enough to be embedded inside programs exploring large cosmological parameter spaces through the Cℓ(z1,z2) comparison with data. We emphasize that the Limber’s approximation, often used to speed up the computation, gives incorrect Cℓ values for cross-correlations.
Les 40es Journées de la SFSPM se sont tenues à Avignon du 7 au 9 novembre 2018. Le thème abordé—Cancer du sein : optimisation du parcours de soins — a réuni plus de 1 200 participants sous les voûtes ...du Palais des Papes. La fluidité de chaque segment du parcours a été analysée en termes de risques de rupture de continuité des soins tant au sein du segment lui-même qu’en amont et en aval. Dans un parcours par essence pluridisciplinaire et plurimétiers, la nécessité d’une réflexion globale et d’une coordination active réalisées par des professionnels formés a été rappelée à chaque session. Chacun des intervenants a esquissé de potentiels indicateurs de qualité tenant compte à la fois de son implication dans son segment d’intervention, mais tenant compte aussi d’une vision plus globale de ce que devrait être le parcours au travers de la maladie et des soins. La parole a été très largement partagée entre soignants et associations de malades, entre paramédicaux et acteurs en sciences humaines et sociales, entre responsables de la santé publique HAS, ARS, CNAM–CPAM 84 et représentants des différents modes d’hospitalisation publique/privée et ESPIC. La session grand public a été l’occasion d’échanges fructueux et instructifs sur la perception des difficultés comme des satisfactions rencontrées que nous ont fait partager les malades, leurs proches et les représentantes des associations. Au total, un congrès de réflexion partagé par de nombreux acteurs qui cherchent tous à améliorer le parcours de soins des malades atteintes de cancer du sein. La publication le 21 janvier par l’INCa de dix indicateurs de qualité du parcours de soins pour les malades atteints de cancer du sein est une étape importante qu’attendaient tous les participants d’Avignon — SFSPM 2018.
The 40th SFSPM conference was held in Avignon from 7 to 9 November 2018. The topics addressed—Breast Cancer: Optimisation of the Care Process — brought together more than 1,200 participants under the vaults of the Palais des Papes. The fluidity of each process segment was analysed in terms of risks to the continuity of care within the segment itself, and both upstream and downstream. In a multidisciplinary and multi-professional process, the need for global reflection and active coordination by trained professionals was emphasised at each session. Each speaker outlined potential quality indicators, taking into account both their involvement in their intervention segment and also taking into account a more global view of what the journey through illness and care should be. The talk time was widely shared between caregivers and patient associations, between medical paraprofessionals and stakeholders in the humanities and social sciences, between public health officials HAS, ARS, CNAM−CPAM 84 and representatives from the different modes of private public hospitalisation and ESPIC. The public session was an opportunity for constructive and informative exchanges about perceptions of both the difficulties and satisfactions encountered that patients, their relatives and representatives of associations shared with us. Overall, a conference for shared reflection between many stakeholders, all seeking to improve the care process for breast cancer patients. The INCa publication on 21 January covering 10 quality indicators of the care process for breast cancer patients is an important milestone eagerly awaited by all Avignon participants — SFSPM 2018.
Cytokine therapy for cancer or viral diseases is accompanied by the development of depressive symptoms in a significant proportion of patients. Despite the increasing number of studies on the ...neurotoxic effects of cytokines, the mechanisms by which cytokines induce depressive symptoms remain largely unknown. In view of the relationship between neurotransmitter precursors and mood, the present study aimed at assessing the relationship between serum concentrations of the amino acids tryptophan and tyrosine, major precursors of serotonin and norepinephrine respectively, and depressive symptoms in cancer patients undergoing cytokine therapy. Sixteen cancer patients eligible to receive immunotherapy with interleukin-2 and/or interferon-alpha participated in the study. At baseline and after one week and one month of therapy, depressive symptoms were assessed using the Montgomery-Asberg Depression Rating Scale (MADRS), and blood samples were collected for the determination of the large neutral amino acids (LNAA) (tryptophan, tyrosine, valine, leucine, isoleucine, phenylalanine) which compete for transport across the blood-brain barrier. Serum concentrations of tryptophan as well as the tryptophan/LNAA ratio significantly decreased between baseline, one week and one month of therapy. The development and severity of depressive symptoms, especially anorexia, pessimistic thoughts, suicidal ideation and loss of concentration were positively correlated with the magnitude of the decreases in tryptophan concentrations during treatment. These findings indicate that the development of depressive symptoms in patients undergoing cytokine therapy could be mediated by a reduced availability of the serotonin relevant amino acid precursor, tryptophan.
Context. The interstellar medium (ISM) is now widely acknowledged to display features ascribable to magnetized turbulence. With the public release of Planck data and the current balloon-borne and ...ground-based experiments, the growing amount of data tracing the polarized thermal emission from Galactic dust in the submillimetre provides choice diagnostics to constrain the properties of this magnetized turbulence. Aims. We aim to constrain these properties in a statistical way, focussing in particular on the power spectral index βB of the turbulent component of the interstellar magnetic field in a diffuse molecular cloud, the Polaris Flare. Methods. We present an analysis framework based on simulating polarized thermal dust emission maps using model dust density (proportional to gas density nH) and magnetic field cubes, integrated along the line of sight (LOS), and comparing these statistically to actual data. The model fields are derived from fractional Brownian motion (fBm) processes, which allows a precise control of their one- and two-point statistics. The parameters controlling the model are (1)–(2) the spectral indices of the density and magnetic field cubes, (3)–(4) the RMS-to-mean ratios for both fields, (5) the mean gas density, (6) the orientation of the mean magnetic field in the plane of the sky (POS), (7) the dust temperature, (8) the dust polarization fraction, and (9) the depth of the simulated cubes. We explore the nine-dimensional parameter space through a Markov chain Monte Carlo analysis, which yields best-fitting parameters and associated uncertainties. Results. We find that the power spectrum of the turbulent component of the magnetic field in the Polaris Flare molecular cloud scales with wavenumber as k−βB with a spectral index βB = 2.8 ± 0.2. It complements a uniform field whose norm in the POS is approximately twice the norm of the fluctuations of the turbulent component, and whose position angle with respect to the north-south direction is χ0 ≈−69°. The density field nH is well represented by a log-normally distributed field with a mean gas density 〈nH〉≈40 cm−3$\left\langle{n_{\mathrm{H}}}\right\rangle \approx 40\,\mathrm{cm}^{-3}$〈 nH 〉≈40 cm−3, a fluctuation ratio σnH/〈nH〉≈1.6$\sigma_{{n_{\mathrm{H}}}/\langle{n_{\mathrm{H}}}\rangle\approx 1.6$σnH/〈nH〉≈1.6 , and a power spectrum with an index βn=1.7−0.3+0.4 $\beta_n=1.7^{+0.4}_{-0.3}$βn=1.7−0.3+0.4 . We also constrain the depth of the cloud to be d ≈ 13 pc, and the polarization fraction p0 ≈ 0.12. The agreement between the Planck data and the simulated maps for these best-fitting parameters is quantified by a χ2 value that is only slightly larger than unity. Conclusions. We conclude that our fBm-based model is a reasonable description of the diffuse, turbulent, magnetized ISM in the Polaris Flare molecular cloud, and that our analysis framework is able to yield quantitative estimates of the statistical properties of the dust density and magnetic field in this cloud.
Aims. The Galileon model is a modified gravity theory that may provide an explanation for the accelerated expansion of the Universe. This model does not suffer from instabilities or ghost problems ...(normally associated with higher-order derivative theories), restores local General Relativity – thanks to the Vainshtein screening effect – and predicts late-time acceleration of the expansion. Methods. We derive a new definition of the Galileon parameters that allows us to avoid having to choose initial conditions for the Galileon field. We tested this model against precise measurements of the cosmological distances and the rate of growth of cosmic structures. Results. We observe a weak tension between the constraints set by growth data and those from distances. However, we find that the Galileon model remains consistent with current observations and is still competitive with the ΛCDM model, contrary to what was concluded in recent publications.
Context. In the next decade, many optical surveys will aim to answer the question of the nature of dark energy by measuring its equation-of-state parameter at the per mill level. This requires ...trusting the photometric calibration of the survey with a precision never reached so far on many sources of systematic uncertainties. The measurement of the on-site atmospheric transmission for each exposure, or for each season or for the full survey on average, can help reach the per mill precision for the magnitudes. Aims. This work aims at proving the ability to use slitless spectroscopy for standard-star spectrophotometry and its use to monitor on-site atmospheric transmission as needed, for example, by the Vera C. Rubin Observatory Legacy Survey of Space and Time supernova cosmology program. We fully deal with the case of a disperser in the filter wheel, which is the configuration chosen in the Rubin Auxiliary Telescope. Methods. The theoretical basis of slitless spectrophotometry is at the heart of our forward-model approach to extract spectroscopic information from slitless data. We developed a publicly available software called Spectractor , which implements each ingredient of the model and finally performs a fit of a spectrogram model directly on image data to obtain the spectrum. Results. We show through simulations that our model allows us to understand the structure of spectrophotometric exposures. We also demonstrate its use on real data by solving specific issues and illustrating that our procedure allows the improvement of the model describing the data. Finally, we discuss how this approach can be used to directly extract atmospheric transmission parameters from the data and thus provide the base for on-site atmosphere monitoring. We show the efficiency of the procedure in simulations and test it on the limited available data set.
ABSTRACT
We report in this paper the test of a plane holographic optical element to be used as an aberration-corrected grating for a slitless spectrograph, inserted in a convergent telescope beam. ...Our long-term objective is the optimization of a specific hologram to switch the auxiliary telescope imager of the Vera Rubin Observatory into an accurate slitless spectrograph, dedicated to the atmospheric transmission measurement. We present and discuss here the promising results of tests performed with prototype holograms at the CTIO $0.9\,$m telescope during a run of 17 nights in 2017 May–June. After their on-sky geometrical characterization, the performances of the holograms as aberration-balanced dispersive optical elements have been established by analysing spectra obtained from spectrophotometric standard stars and narrow-band emitter planetary nebulae. Thanks to their additional optical function, our holographic disperser prototypes allow us to produce significantly better focused spectra within the full visible wavelength domain $370,1050\,$nm than a regular grating, which suffers from strong defocusing and aberrations when used in similar conditions. We show that the resolution of our slitless on-axis spectrograph equipped with the hologram approaches its theoretical performance. While estimating the benefits of a hologram for the spectrum resolution, the roadmap to produce a competitive holographic element for the Vera Rubin Observatory auxiliary telescope has been established.
In the near future, cosmology will enter the wide and deep galaxy survey era, enabling high-precision studies of the large-scale structure of the universe in three dimensions. To test cosmological ...models and determine their parameters accurately, it is necessary to use data with exact theoretical expectations expressed in observational parameter space (angles and redshift). The data-driven, galaxy number count fluctuations on redshift shells can be used to build correlation functions on and between shells to probe the baryonic acoustic oscillations and distance-redshift distortions, as well as gravitational lensing and other relativistic effects. To obtain a numerical estimation of from a cosmological model, it is typical to use either a closed form derived from a tripolar spherical expansion or to compute the power spectrum and perform a Legendre polynomial expansion. Here, we present a new derivation of a closed form using the spherical harmonic expansion and proceeding to an infinite sum over multipoles thanks to an addition theorem. We demonstrate that this new expression is perfectly compatible with the existing closed forms but is simpler to establish and manipulate. We provide formulas for the leading density and redshift-space contributions, but also show how Doppler-like and lensing terms can be easily included in this formalism. We have implemented and made publicly available software for computing those correlations efficiently, without any Limber approximation, and validated this software with the CLASSgal code. It is available at https://gitlab.in2p3.fr/campagne/AngPow.
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