(E)-2-{[1-(3,11-Dimethyl-4-methylene- 10-oxo-1-phenyl-4,5,10,11-tetrahydro-1H-benzo[b]pyrazolo[3,4-f][1,5]diazocin- 5-yl)ethylidene]amino}-N-methyl-N-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-benzamide

The central eight-membered ring of the title compound,C40H36N8O2, deviates from the ideal boat conformation because the bond between the exo-ethylene group and the adjacent N atom is twisted by 60.0 (4)° due to steric hindrance. Its adjacent benzene and pyrazole rings are oriented almost perpendicular to each other, making a dihedral angle of 85.8 (3)°. In the crystal, the molecules are linked by C(ar)— H...O hydrogen bonds, generating a three-dimensional networ

Arc sensitivity to cluster ellipticity, asymmetries and substructures

We investigate how ellipticity, asymmetries and substructures separately affect the ability of galaxy clusters to produce strong lensing events, i.e. gravitational arcs, and how they influence the arc morphologies and fluxes. This is important for those studies aiming, for example, at constraining cosmological parameters from statistical lensing, or at determining the inner structure of galaxy clusters through gravitational arcs. We do so by creating two-dimensional gradually smoothed, differently elliptical and asymmetric versions of some numerical models. On average, we find that the contributions of ellipticity, asymmetries and substructures amount to ~40%, ~10% and ~30% of the total strong lensing cross section, respectively. However, our analysis shows that substructures play a more important role in less elliptical and asymmetric clusters, even if located at large distances from the cluster centers (~1Mpc/h). Conversely, their effect is less important in highly asymmetric lenses. The morphology, position and flux of individual arcs are strongly affected by the presence of substructures in the clusters. Removing substructures on spatial scales <~50kpc/h, roughly corresponding to mass scales <~5 10^{10}M_\odot/h, alters the image multiplicity of ~35% of the sources used in the simulations and causes position shifts larger than 5'' for ~40% of the arcs longer than 5''. We conclude that any model for cluster lens cannot neglect the effects of ellipticity, asymmetries and substructures. On the other hand, the high sensitivity of gravitational arcs to deviations from regular, smooth and symmetric mass distributions suggests that strong gravitational lensing is potentially a powerfull tool to measure the level of substructures and asymmetries in clusters.Comment: 16 pages, 18 figures. Accepted version. Version with full resolution images can be found at http://www.ita.uni-heidelberg.de/~massimo/sub/publications.htm

Strong lensing in the MareNostrum Universe: biases in the cluster lens population

Strong lensing is one of the most direct probes of the mass distribution in the inner regions of galaxy clusters. It can be used to constrain the density profiles and to measure the mass of the lenses. Moreover, the abundance of strong lensing events can be used to constrain the structure formation and the cosmological parameters through the so-called "arc-statistics" approach. However, several issues related to the usage of strong lensing clusters in cosmological applications are still controversial, leading to the suspect that several biases may affect this very peculiar class of objects. With this study we aim at better understanding the properties of galaxy clusters which can potentially act as strong lenses. We do so by investigating the properties of a large sample of galaxy clusters extracted from the N-body/hydrodynamical simulation MareNostrum Universe. We explore the correlation between the cross section for lensing and many properties of clusters, like the mass, the three-dimensional and projected shapes, their concentrations, the X-ray luminosity and the dynamical activity. We find that the probability of strong alignments between the major axes of the lenses and the line of sight is a growing function of the lensing cross section. In projection, the strong lenses appear rounder within R200, but we find that their cores tend to be more elliptical as the lensing cross section increases. We also find that the cluster concentrations estimated from the projected density profiles tend to be biased high. The X-ray luminosity of strong lensing clusters is higher than that of normal lenses of similar mass and redshift. This is particular significant for the least massive lenses. Finally, we find that the strongest lenses generally exhibit an excess of kinetic energy within the virial radius, indicating that they are more dynamically active than usual clusters.Comment: 22 pages, 18 figures, accepted for publication on A&

Accuracy of photometric redshifts for future weak lensing surveys from space

Photometric redshifts are a key tool to extract as much information as possible from planned cosmic shear experiments. In this work we aim to test the performances that can be achieved with observations in the near-infrared from space and in the optical from the ground. This is done by performing realistic simulations of multi-band observations of a patch of the sky, and submitting these mock images to software usually applied to real images to extract the photometry and then a redshift estimate for each galaxy. In this way we mimic the most relevant sources of uncertainty present in real data analysis, including blending and light pollution between galaxies. As an example we adopt the infrared setup of the ESA-proposed Euclid mission, while we simulate different observations in the optical, modifying filters, exposure times and seeing values. Finally, we consider directly some future ground-based experiments, such as LSST, Pan-Starrs and DES. The results highlight the importance of u-band observations, especially to discriminate between low (z < 0.5) and high (z ~ 3) redshifts, and the need for good observing sites, with seeing FWHM < 1. arcsec. The former of these indications clearly favours the LSST experiment as a counterpart for space observations, while for the other experiments we need to exclude at least 15 % of the galaxies to reach a precision in the photo-zs equal to $$ < 0.05.Comment: 11 pages, to be published in MNRAS. Minor changes to match the published versio

Mass profiles and concentration-dark matter relation in X-ray luminous galaxy clusters

(Abriged) Assuming that the hydrostatic equilibrium holds between the intracluster medium and the gravitational potential, we constrain the NFW profiles in a sample of 44 X-ray luminous galaxy clusters observed with XMM-Newton in the redshift range 0.1-0.3. We evaluate several systematic uncertainties that affect our reconstruction of the X-ray masses. We measure the concentration c200, the dark mass M200 and the gas mass fraction within R500 in all the objects of our sample, providing the largest dataset of mass parameters for galaxy clusters in this redshift range. We confirm that a tight correlation between c200 and M200 is present and in good agreement with the predictions from numerical simulations and previous observations. When we consider a subsample of relaxed clusters that host a Low-Entropy-Core (LEC), we measure a flatter c-M relation with a total scatter that is lower by 40 per cent. From the distribution of the estimates of c200 and M200, with associated statistical (15-25%) and systematic (5-15%) errors, we use the predicted values from semi-analytic prescriptions calibrated through N-body numerical runs and measure sigma_8*Omega_m^(0.60+-0.03)= 0.45+-0.01 (at 2 sigma level, statistical only) for the subsample of the clusters where the mass reconstruction has been obtained more robustly, and sigma_8*Omega_m^(0.56+-0.04) = 0.39+-0.02 for the subsample of the 11 more relaxed LEC objects. With the further constraint from the fgas distribution in our sample, we break the degeneracy in the sigma_8-Omega_m plane and obtain the best-fit values sigma_8~1.0+-0.2 (0.75+-0.18 when the subsample of the more relaxed objects is considered) and Omega_m = 0.26+-0.01.Comment: 21 pages. A&A in press. Minor revisions to match accepted version. Corrected 2nd and 3rd column in Table 3, and equation (A.4

Weighing simulated galaxy clusters using lensing and X-ray

We aim at investigating potential biases in lensing and X-ray methods to measure the cluster mass profiles. We do so by performing realistic simulations of lensing and X-ray observations that are subsequently analyzed using observational techniques. The resulting mass estimates are compared among them and with the input models. Three clusters obtained from state-of-the-art hydrodynamical simulations, each of which has been projected along three independent lines-of-sight, are used for this analysis. We find that strong lensing models can be trusted over a limited region around the cluster core. Extrapolating the strong lensing mass models to outside the Einstein ring can lead to significant biases in the mass estimates, if the BCG is not modeled properly for example. Weak lensing mass measurements can be largely affected by substructures, depending on the method implemented to convert the shear into a mass estimate. Using non-parametric methods which combine weak and strong lensing data, the projected masses within R200 can be constrained with a precision of ~10%. De-projection of lensing masses increases the scatter around the true masses by more than a factor of two due to cluster triaxiality. X-ray mass measurements have much smaller scatter (about a factor of two smaller than the lensing masses) but they are generally biased low by 5-20%. This bias is ascribable to bulk motions in the gas of our simulated clusters. Using the lensing and the X-ray masses as proxies for the true and the hydrostatic equilibrium masses of the simulated clusters and averaging over the cluster sample we are able to measure the lack of hydrostatic equilibrium in the systems we have investigated.Comment: 27 pages, 21 figures, accepted for publication on A&A. Version with full resolution images can be found at http://pico.bo.astro.it/~massimo/Public/Papers/massComp.pd

Arc Statistics in Cosmological Models with Dark Energy

We investigate how the probability of the formation of giant arcs in galaxy clusters is expected to change in cosmological models dominated by dark energy with an equation of state p=w rho c^2 compared to cosmological-constant or open models. To do so, we use a simple analytic model for arc cross sections based on the Navarro-Frenk-White density profile which we demonstrate reproduces essential features of numerically determined arc cross sections. Since analytic lens models are known to be inadequate for accurate absolute quantifications of arc probabilities, we use them only for studying changes relative to cosmological-constant models. Our main results are (1) the order of magnitude difference between the arc probabilities in low density, spatially flat and open CDM models found numerically is reproduced by our analytic model, and (2) dark-energy cosmologies with w>-1 increase the arc optical depth by at most a factor of two and are thus unlikely to reconcile arc statistics with spatially flat cosmological models with low matter density.Comment: 8 pages, accepted by A&

Testing the reliability of weak lensing cluster detections

We study the reliability of dark-matter halo detections with three different linear filters applied to weak-lensing data. We use ray-tracing in the multiple lens-plane approximation through a large cosmological simulation to construct realizations of cosmic lensing by large-scale structures between redshifts zero and two. We apply the filters mentioned above to detect peaks in the weak-lensing signal and compare them with the true population of dark matter halos present in the simulation. We confirm the stability and performance of a filter optimized for suppressing the contamination by large-scale structure. It allows the reliable detection of dark-matter halos with masses above a few times 1e13 M_sun/h with a fraction of spurious detections below ~10%. For sources at redshift two, 50% of the halos more massive than ~7e13 M_sun/h are detected, and completeness is reached at ~2e14 M_sun/h.Comment: 14 pages, 13 figures, accepted on A&

Trajectories across the healthy adult lifespan on sense of direction, spatial anxiety, and attitude in exploring places

Introduction: Self-evaluations about orientation and navigation in the environment contribute to individual differences in spatial cognition. Evidence suggests that they may change, even slightly, with the progression of adulthood. It is necessary to improve the framing of environment-related subjective self-evaluations in adulthood and aging by examining how they change and the factors related to them. Therefore, this study aimed to examine the developmental trajectories of sense of direction, spatial anxiety, and attitude in exploring place across the adult lifespan while also considering gender and education. Materials and methods: A sample of 1,946 participants (1,068 women), aged 18–87 years, completed the sense of direction and spatial representation, spatial anxiety, and attitude in exploring scales. Results: The regression models showed a linear increase in sense of direction with age, stable spatial anxiety until age 66 years when anxiety began increasing, and a stable attitude in exploring with a deflection by age 71 years. Gender played a role in all three types of self-evaluations, with men reporting higher ratings in sense of direction and attitude toward exploring (especially in older men), and lower levels of spatial anxiety than women did. Education also played a role, with higher education years associated with lower ratings in spatial anxiety and a higher sense of direction, nullifying gender differences in the latter. Discussion: These results offer, in the spatial cognition framework, a better understanding of how specific environment-related self-evaluations develop with age and related factors, such as education. This underscores the importance of enhancing them, particularly in women and older adults