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We analysed spectroscopic data obtained with VLT-VIMOS for two multiple-cluster systems, PLCKG$214.6+36.9$ and PLCKG$334.8-38.0$, discovered via their thermal Sunyaev-Zel'dovich signal by $Planck$. Combining the Optical spectroscopy, for the redshift determination, and photometric data from galaxy surveys (SDSS, WISE, DESI), we were able to study the structure of the two multiple-cluster systems, to determine their nature and the properties of their member galaxies. We found that the two systems are populated mainly with passive galaxies and that PLCKG$214.6+36.9$ consists of a pair of clusters at redshift $z = 0.445$ and a background isolated cluster at $z = 0.498$, whereas the system PLCKG$334.8-38.0$ is a chance association of three independent clusters at redshifts $z = 0.367$, $z =0.292$, and $z = 0.33$. We also find evidence for remaining star formation activity in the highest-redshift cluster of PLCKG$214.6+36.9$, at $z = 0.498$., Comment: 12 pages, 9 Figures, 5 Tables. Submitted to A&A, comments are welcome

The gas mass fraction in galaxy clusters is a convenient probe to use in cosmological studies, as it can help derive constraints on a collection of cosmological parameters. It is however subject to various effects from the baryonic physics inside galaxy clusters, which may bias the obtained cosmological constraints. Among different aspects of the baryonic physics, in this paper we focus on the impact of the hydrostatic equilibrium assumption. We analyse the hydrostatic mass bias $B$, constraining a possible mass and redshift evolution of this quantity and its impact on the cosmological constraints. To that end we consider cluster observations of the {\it Planck}-ESZ sample and evaluate the gas mass fraction using X-ray counterpart observations. We show a degeneracy between the redshift dependence of the bias and cosmological parameters. In particular we find a $3.8 \sigma$ evidence for a redshift dependence of the bias when assuming a {\it Planck} prior on $\Omega_m$. On the other hand, assuming a constant mass bias would lead to the extreme large value of $\Omega_m > 0.849$. We however show that our results are entirely dependent on the cluster sample we consider. In particular, the mass and redshift trends that we find for the lowest mass-redshift and highest mass-redshift clusters of our sample are not compatible. Nevertheless, in all the analyses we find a value for the amplitude of the bias that is consistent with $B \sim 0.8$, as expected from hydrodynamical simulations and local measurements, but still in tension with the low value of $B \sim 0.6$ derived from the combination of cosmic microwave background primary anisotropies with cluster number counts., Comment: 24 pages, 14 figures, 6 tables. Accepted in A&A. Baryon fraction table available at http://szcluster-db.ias.u-psud.fr and https://byopic.eu/tools_and_data

Significant research and press has recently focused on the fabrication freedom of Additive Manufacturing (AM) to create both conceptual models and final end-use products. This flexibility allows design modifications to be immediately reflected in 3D printed structures, creating new paradigms within the manufacturing process. 3D printed products will inevitably be fabricated locally, with unit-level customization, optimized to unique mission requirements. However, for the technology to be universally adopted, the processes must be enhanced to incorporate additional technologies; such as electronics, actuation, and electromagnetics. Recently, a novel 3D printing platform, Multi3D manufacturing, was funded by the presidential initiative for revitalizing manufacturing in the USA using 3D printing (America Makes - also known as the National Additive Manufacturing Innovation Institute). The Multi3D system specifically targets 3D printed electronics in arbitrary form; and building upon the potential of this system, this paper describes RF antennas and components fabricated through the integration of material extrusion 3D printing with embedded wire, mesh, and RF elements.