We present a detailed study of the integrated total hydrostatic mass profiles of the five most massive M500SZ < 5 × 1014 M⊙ ( M 500 SZ > 5 × 10 14 M ⊙ ) $\left( {M_{500}^{{\rm{SZ}}} > 5 \times ...{{10}^{14}}\,{M_ \odot }} \right)$ galaxy clusters selected at z ∼ 1 via the Sunyaev–Zel’dovich effect. These objects represent an ideal laboratory to test structure formation models where the primary driver is gravity. Optimally exploiting spatially-resolved spectroscopic information from XMM-Newton and Chandra observations, we used both parametric (forward, backward) and non-parametric methods to recover the mass profiles, finding that the results are extremely robust when density and temperature measurements are both available. Our X-ray masses at R500 are higher than the weak lensing masses obtained from the Hubble Space Telescope (HST), with a mean ratio of 1.39−0.35+0.47 1.39 − 0.35 + 0.47 $1.39^{+0.47}_{-0.35}$ . This offset goes in the opposite direction to that expected in a scenario where the hydrostatic method yields a biased, underestimated, mass. We investigated halo shape parameters such as sparsity and concentration, and compared to local X-ray selected clusters, finding hints for evolution in the central regions (or for selection effects). The total baryonic content is in agreement with the cosmic value at R500. Comparison with numerical simulations shows that the mass distribution and concentration are in line with expectations. These results illustrate the power of X-ray observations to probe the statistical properties of the gas and total mass profiles in this high mass, high-redshift regime.
ABSTRACT
The dark matter halo sparsity, i.e. the ratio between spherical halo masses enclosing two different overdensities, provides a non-parametric proxy of the halo mass distribution that has been ...shown to be a sensitive probe of the cosmological imprint encoded in the mass profile of haloes hosting galaxy clusters. Mass estimations at several overdensities would allow for multiple sparsity measurements, which can potentially retrieve the entirety of the cosmological information imprinted on the halo profile. Here, we investigate the impact of multiple sparsity measurements on the cosmological model parameter inference. For this purpose, we analyse N-body halo catalogues from the Raygal and M2Csims simulations and evaluate the correlations among six different sparsities from spherical overdensity halo masses at Δ = 200, 500, 1000, and 2500 (in units of the critical density). Remarkably, sparsities associated to distinct halo mass shells are not highly correlated. This is not the case for sparsities obtained using halo masses estimated from the Navarro-Frenk-White (NFW) best-fitting profile, which artificially correlates different sparsities to order one. This implies that there is additional information in the mass profile beyond the NFW parametrization and that it can be exploited with multiple sparsities. In particular, from a likelihood analysis of synthetic average sparsity data, we show that cosmological parameter constraints significantly improve when increasing the number of sparsity combinations, though the constraints saturate beyond four sparsity estimates. We forecast constraints for the CHEX-MATE cluster sample and find that systematic mass bias errors mildly impact the parameter inference, though more studies are needed in this direction.
The efficiency of shear walls to sustain the earthquake loads mainly depends on the aspect ratio, the vertical load, and the ratios of longitudinal and transverse reinforcement. In this paper, two ...lightly reinforced concrete walls have been experimentally and numerically investigate with an aspect ratio equal to 0.67 (short wall) and 2.5 (slender wall). Different retrofitting strategies have been considered using Carbon-Fiber-Reinforced-Polymer (CFRP) materials. Pushover analyses have been carried out using two advanced numerical approaches for the concrete modeling: the first one adopts a 2D plane stress approach with a local concrete model based on the smeared fixed crack approach and a classical regularization technique based on the fracture energy; the second investigates a coupled elastoplastic damage model using local approach in 2D and 3D simulations. The numerical results in terms of the load–displacements are very consistent with experimental data. The observed failure modes and crack patterns are satisfactorily reproduced for both walls, without or with the CFRP strengthening.
We report the study of a resonant bandpass filter made of a very thin subwavelength metal patch array coupled to a high index dielectric waveguide. The spectral properties of those filters can easily ...be tuned by playing on the lateral dimensions of the grating. They exhibit high and narrow transmission peaks together with very good rejection of light out of the pass-band and low angular dependance. An experimental demonstration using standard large scale silicon microelectronics processes is presented in the mid infrared spectral range. This concept of filters can easily be scaled throughout the optical spectrum, and can be integrated within focal plane arrays of various imaging technologies, down to visible wavelengths.
ABSTRACT
The effects of maternal nutrition on offspring phenotypes have been mainly documented over the past years in mammals, and are now studied in poultry as well. In the present study, we ...investigated the effects of a reduced level of dietary Methionine (Met) on laying performances of common laying ducks and their impacts on the phenotype of their mule ducklings. A total of 60 female laying ducks were divided into 2 dietary treatments at 10 wk of age. The restricted group received Met-restricted diets (R group) containing 0.25% of Met whereas the control group received control diets (C group) containing 0.40% of Met that meets Met requirements. The restriction was applied during the growing and laying periods, from 10 to 51 wk of age and a particular focus was put on female breeder traits that might be affected by the Met restriction. Plasma parameters of hepatic and lipid metabolisms were recorded in ducklings. Total weight (P < 0.001), albumen weight (P < 0.001) and albumen percentage of dry matter (P < 0.01) were decreased for eggs laid by female breeders from the R group. Both male and female ducklings from the R group of female breeders showed a reduced BW at hatching (P < 0.001) and a tendency to an increased proportional liver weight (P = 0.07). Finally, the maternal low dietary Met level modified plasma parameters in newborn ducklings regardless of sex: alkaline phosphatase (ALP) and alanine transaminase (ALT) activities were reduced (P = 0.07 and P = 0.002, respectively), levels of glucose (P = 0.03) and triglycerides (P = 0.01) were higher whereas level of free fatty acids decreased (P = 0.01). It was concluded that feeding female laying ducks with a restricted dietary Met content during the growing and laying periods has a negative effect on egg weight and composition. The ducklings that were restricted in nutrients during their early development, have a reduced BW, and altered lipid and hepatic metabolisms.
The XXL Survey Faccioli, L.; Pacaud, F.; Sauvageot, J.-L. ...
Astronomy and astrophysics (Berlin),
12/2018, Letnik:
620
Journal Article
Recenzirano
Odprti dostop
Aims. A well characterised detection pipeline is an important ingredient for X-ray cluster surveys. Methods. We present the final development of the XXL Survey pipeline. The pipeline optimally uses ...X-ray information by combining many overlapping observations of a source when possible, both for its detection and its characterisation. It can robustly detect and characterise several types of X-ray sources: AGNs (point-like), galaxy clusters (extended), galaxy clusters contaminated by a central AGN, and pairs of AGNs close on the sky. We perform a thorough suite of validation tests via realistic simulations of XMM-Newton images and we introduce new selection criteria for various types of sources that will be detected by the survey. Results. We find that the use of overlapping observations allows new clusters to be securely identified that would be missed or less securely identified by using only one observation at a time. We also find that, with the new pipeline we can robustly identify clusters with a central AGN that would otherwise have been missed, and we can flag pairs of AGNs close on the sky that might have been mistaken for a cluster.
The XXL Survey Koulouridis, E.; Faccioli, L.; Le Brun, A. M. C. ...
Astronomy and astrophysics (Berlin),
12/2018, Letnik:
620
Journal Article
Recenzirano
Odprti dostop
Modern cosmological simulations heavily rely on feedback from active galactic nuclei (AGN) in order to stave off overcooling in massive galaxies, and galaxy groups and clusters. Given that AGN are a ...key component of such simulations, an important independent test is whether or not the simulations capture the broad demographics of the observed AGN population. However, to date, comparisons between observed and simulated AGN populations have been relatively limited. Here, we have used the cosmo-OWLS suite of cosmological hydrodynamical simulations to produce realistic synthetic catalogs of X-ray AGN out to
z
= 3, with the aim of comparing the catalogs to the observed X-ray AGN population in the XXL survey and other recent surveys. We focused on the unabsorbed X-ray luminosity function (XLF), the Eddington ratio distribution, the black hole mass function, and the projected clustering of X-ray AGN. To compute the unabsorbed XLF of the simulated AGN, we used recent empirically-determined (luminosity-dependent) bolometric corrections, in order to convert the simulated bolometric luminosity into an observable X-ray luminosity. We show that, using these corrections, the simulated AGN sample accurately reproduces the observed XLF over 3 orders of magnitude in X-ray luminosity in all redshift bins from
z
= 0 out to
z
= 3. To compare to the observed Eddington ratio distribution and the clustering of AGN, we produced detailed “
XMM-Newton
-detected” catalogs of the simulated AGN. This requires the production of synthetic X-ray images extracted from light cones of the simulations, which self-consistently contain both the X-ray AGN and the emission from diffuse, hot gas within galaxies, galaxy groups, and clusters and that fold in the relevant instrumental effects of
XMM-Newton
. We apply a luminosity- and redshift-dependent obscuration function for the AGN and employ the same AGN detection algorithm as used for the real XXL survey. We demonstrate that the detected population of simulated AGN reproduces the observed Eddington ratio distribution and projected clustering from XXL quite well. Based on these comparisons, we conclude that the simulations have a broadly realistic population of AGN and that our synthetic X-ray AGN catalogs should be useful for interpreting additional trends (e.g. environmental dependencies) and as a helpful tool for quantifying AGN contamination in galaxy group and cluster X-ray surveys.
The XXL Survey Koulouridis, E.; Faccioli, L.; Le Brun, A. M. C. ...
Astronomy and astrophysics (Berlin),
12/2018, Letnik:
620
Journal Article
Recenzirano
Odprti dostop
Modern cosmological simulations heavily rely on feedback from active galactic nuclei (AGN) in order to stave off overcooling in massive galaxies, and galaxy groups and clusters. Given that AGN are a ...key component of such simulations, an important independent test is whether or not the simulations capture the broad demographics of the observed AGN population. However, to date, comparisons between observed and simulated AGN populations have been relatively limited. Here, we have used the cosmo-OWLS suite of cosmological hydrodynamical simulations to produce realistic synthetic catalogs of X-ray AGN out to z = 3, with the aim of comparing the catalogs to the observed X-ray AGN population in the XXL survey and other recent surveys. We focused on the unabsorbed X-ray luminosity function (XLF), the Eddington ratio distribution, the black hole mass function, and the projected clustering of X-ray AGN. To compute the unabsorbed XLF of the simulated AGN, we used recent empirically-determined (luminosity-dependent) bolometric corrections, in order to convert the simulated bolometric luminosity into an observable X-ray luminosity. We show that, using these corrections, the simulated AGN sample accurately reproduces the observed XLF over 3 orders of magnitude in X-ray luminosity in all redshift bins from z = 0 out to z = 3. To compare to the observed Eddington ratio distribution and the clustering of AGN, we produced detailed “XMM-Newton-detected” catalogs of the simulated AGN. This requires the production of synthetic X-ray images extracted from light cones of the simulations, which self-consistently contain both the X-ray AGN and the emission from diffuse, hot gas within galaxies, galaxy groups, and clusters and that fold in the relevant instrumental effects of XMM-Newton. We apply a luminosity- and redshift-dependent obscuration function for the AGN and employ the same AGN detection algorithm as used for the real XXL survey. We demonstrate that the detected population of simulated AGN reproduces the observed Eddington ratio distribution and projected clustering from XXL quite well. Based on these comparisons, we conclude that the simulations have a broadly realistic population of AGN and that our synthetic X-ray AGN catalogs should be useful for interpreting additional trends (e.g. environmental dependencies) and as a helpful tool for quantifying AGN contamination in galaxy group and cluster X-ray surveys.
We investigate the evolution of the dark matter density profiles of the most massive galaxy clusters in the Universe. Using a ‘zoom-in’ procedure on a large suite of cosmological simulations of total ...comoving volume of 3 (
h
-1
Gpc)
3
, we study the 25 most massive clusters in four redshift slices from
z
~ 1 to the present. The minimum mass is
M
500
> 5:5 × 10
14
M
⊙
at
z
= 1. Each system has more than two million particles within
r
500
. Once scaled to the critical density at each redshift, the dark matter profiles within
r
500
are strikingly similar from
z
~ 1 to the present day, exhibiting a low dispersion of 0.15 dex, and showing little evolution with redshift in the radial logarithmic slope and scatter. They have the running power law shape typical of the NFW-type profiles, and their inner structure, resolved to 3:8
h
-1
comoving kpc at
z
= 1, shows no signs of converging to an asymptotic slope. Our results suggest that this type of profile is already in place at
z
> 1 in the highest-mass haloes in the Universe, and that it remains exceptionally robust to merging activity.
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