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The study of the morphology of 2D projected maps of galaxy clusters is a suitable approach to infer, from real data, the dynamical state of those systems. We recently developed a new method to recover the morphological features in galaxy cluster maps which consists of an analytical modelling through the Zernike polynomials. The validation of this approach was done on a set of high-resolution mock maps of the Compton parameter y . These maps are from hydrodynamically simulated galaxy clusters in The Three Hundred project. After this step, we apply the Zernike modelling on y -maps of local ( z < 0.1) galaxy clusters observed by the Planck satellite. With a single parameter collecting the main information of the Zernike modelling, we classify their morphology. A set of mock Planck -like y -maps, generated from The Three Hundred clusters, is also used to validate our indicator with a proper dynamical state classification. This approach allows us to test the efficiency of the Zernike morphological modelling in evaluating the dynamical population in the real Planck sample.

The MIllimeter Sardinia radio Telescope Receiver based on Array of Lumped elements KIDs, MISTRAL, is a cryogenic LEKID camera, operating in the W band ( 77 - 103 GHz ) from the Gregorian focus of the 64-m aperture Sardinia Radio Telescope (SRT), in Italy. This instrument features a high angular resolution ( ∼ 12 arcsec ) and a wide instantaneous field of view ( ∼ 4 arcmin ), allowing continuum surveys of the mm-wave sky with many scientific targets, including observations of galaxy clusters via the Sunyaev–Zel’dovich effect. In May 2023, MISTRAL has been installed at SRT for the technical commissioning. In this contribution, we will describe the MISTRAL instrument focusing on the laboratory characterization of its focal plane: a ∼ 400 -pixel LEKID array. We will show the optical performance of the detectors highlighting the procedure for the identification of the pixels on the focal plane, the measurements of the optical responsivity and NEP, and the estimation of the optical efficiency.

We describe the design and performance of the cryostat and the multi-stage sub-K single-shot sorption cooler for the MIllimeter Sardinia Radio Telescope Receiver based on Array of Lumped elements kids (MISTRAL) experiment. MISTRAL is a W-band (77 - 103 GHz) Ti/Al bi-layer Lumped Elements Kinetic Inductance Detectors (LEKIDs) camera working at the Gregorian focus of the 64 m aperture Sardinia Radio Telescope (SRT), located in Sardinia (Italy). The cryogenic system, based on a 1.5 W at 4.2 K Pulse Tube (PT) cryocooler, provides the 4 K base temperature for the sub-K refrigerator, and cools down the cold optics and the filters chain of the instrument. The sub-K sorption cooler consists of two intermediate stages, 4 He and 3 He sorption refrigerators that allow to reduce the heat load on the ultra-cold head, and a twin stage of 3 He sorption refrigerator providing the 0.2 K operation temperature for the 415-pixel array of LEKIDs. MISTRAL experiment was installed at SRT in May 2023, the technical commissioning started in June 2023. We will show the performance of the system in the laboratory.

MISTRAL is a millimetric camera working in the W-band (78–103 GHz) which will take data from the Sardinia Radio Telescope, the Italian 64-m radio telescope located 50 km form Cagliari, at 600m above the sea level, in Sardinia. It is being built as a facility instrument by the Sapienza University for INAF, that manages the radio telescope, under a PON contract. It will consist of a compact cryostat hosting the re–imaging optics, cooled at 4K, and a 408–pixel array of photon–noise limited lumped element kinetic inductance detectors fabricated at CNR-IFN and cooled at a base temperature lower than 300mK. MISTRAL will be able to investigate a long list of scientific targets spanning from extragalactic astrophysics to solar system science, with high angular resolution (~ 12 arcsec), including Sunyaev Zel’dovich effect measurements and the study of the Cosmic Web.

Galaxy clusters and surrounding medium, can be studied using X-ray bremsstrahlung emission and Sunyaev Zel’dovich (SZ) effect. Both astrophysical probes, sample the same environment with different parameters dependance. The SZ effect is relatively more sensitive in low density environments and thus is useful to study the filamentary structures of the cosmic web. In addition, observations of the matter distribution require high angular resolution in order to be able to map the matter distribution within and around galaxy clusters. MISTRAL is a camera working at 90GHz which, once coupled to the Sardinia Radio Telescope (SRT), can reach 12″ angular resolution over 4′ field of view (f.o.v.). The forecasted sensitivity drives to a Noise Equivalent Flux Density of ≃ 10–15 mJy √ s and the mapping speed is MS = 380′ 2 mJy −2 h −1 . MISTRAL was recently installed at the focus of the SRT and soon will take its first photons.

According to CMB measurements, baryonic matter constitutes about \\(5\\%\\) of the mass-energy density of the universe. A significant population of these baryons, for a long time referred to as `missing', resides in a low density, warm-hot intergalactic medium (WHIM) outside galaxy clusters, tracing the ``cosmic web'', a network of large scale dark matter filaments. Various studies have detected this inter-cluster gas, both by stacking and by observing individual filaments in compact, massive systems. In this paper, we study short filaments (< 10 Mpc) connecting massive clusters (\\(M_{500} \\approx 3\\times 10^{14} M_{\\odot}\\)) detected by the Atacama Cosmology Telescope (ACT) using the scattering of CMB light off the ionised gas, a phenomenon known as the thermal Sunyaev-Zeldovich (tSZ) effect. The first part of this work is a search for suitable candidates for high resolution follow-up tSZ observations. We identify four cluster pairs with an intercluster signal above the noise floor (S/N \\(>\\) 2), including two with a tentative \\(>2\\sigma\\) statistical significance for an intercluster bridge from the ACT data alone. In the second part of this work, starting from the same cluster sample, we directly stack on \\({\\sim}100\\) cluster pairs and observe an excess SZ signal between the stacked clusters of \\(y=(7.2^{+2.3}_{-2.5})\\times 10^{-7}\\) with a significance of \\(3.3\\sigma\\). It is the first tSZ measurement of hot gas between clusters in this range of masses at moderate redshift (\\(\\langle z\\rangle\\approx 0.5\\)). We compare this to the signal from simulated cluster pairs with similar redshifts and separations in the THE300 and MAGNETICUM Pathfinder cosmological simulations and find broad consistency. Additionally, we show that our measurement is consistent with scaling relations between filament parameters and mass of the embedded halos identified in simulations.

According to CMB measurements, baryonic matter constitutes about \\(5\\%\\) of the mass-energy density of the universe. A significant population of these baryons, for a long time referred to as `missing', resides in a low density, warm-hot intergalactic medium (WHIM) outside galaxy clusters, tracing the ``cosmic web'', a network of large scale dark matter filaments. Various studies have detected this inter-cluster gas, both by stacking and by observing individual filaments in compact, massive systems. In this paper, we study short filaments (< 10 Mpc) connecting massive clusters (\\(M_{500} \\approx 3\\times 10^{14} M_{\\odot}\\)) detected by the Atacama Cosmology Telescope (ACT) using the scattering of CMB light off the ionised gas, a phenomenon known as the thermal Sunyaev-Zeldovich (tSZ) effect. The first part of this work is a search for suitable candidates for high resolution follow-up tSZ observations. We identify four cluster pairs with an intercluster signal above the noise floor (S/N \\(>\\) 2), including two with a tentative \\(>2\\sigma\\) statistical significance for an intercluster bridge from the ACT data alone. In the second part of this work, starting from the same cluster sample, we directly stack on \\({\\sim}100\\) cluster pairs and observe an excess SZ signal between the stacked clusters of \\(y=(7.2^{+2.3}_{-2.5})\\times 10^{-7}\\) with a significance of \\(3.3\\sigma\\). It is the first tSZ measurement of hot gas between clusters in this range of masses at moderate redshift (\\(\\langle z\\rangle\\approx 0.5\\)). We compare this to the signal from simulated cluster pairs with similar redshifts and separations in the THE300 and MAGNETICUM Pathfinder cosmological simulations and find broad consistency. Additionally, we show that our measurement is consistent with scaling relations between filament parameters and mass of the embedded halos identified in simulations.

Galaxy clusters and surrounding medium, can be studied using X-ray bremsstrahlung emission and Sunyaev Zel'dovich (SZ) effect. Both astrophysical probes, sample the same environment with different parameters dependance. The SZ effect is relatively more sensitive in low density environments and thus is useful to study the filamentary structures of the cosmic web. In addition, observations of the matter distribution require high angular resolution in order to be able to map the matter distribution within and around galaxy clusters. MISTRAL is a camera working at 90GHz which, once coupled to the Sardinia Radio Telescope, can reach \\(12''\\) angular resolution over \\(4'\\) field of view (f.o.v.). The forecasted sensitivity is \\(NEFD \\simeq 10-15mJy \\sqrt{s}\\) and the mapping speed is \\(MS= 380'^{2}/mJy^{2}/h\\). MISTRAL was recently installed at the focus of the SRT and soon will take its first photons.

The MIllimeter Sardinia radio Telescope Receiver based on Array of Lumped elements kids, MISTRAL, is a millimetric (\\(\\simeq 90GHz\\)) multipixel camera being built for the Sardinia Radio Telescope. It is going to be a facility instrument and will sample the sky with 12 arcsec angular resolution, 4 arcmin field of view, through 408 Kinetic Inductance Detectors (KIDs). The construction and the beginning of commissioning is planned to be in 2022. MISTRAL will allow the scientific community to propose a wide variety of scientific cases including protoplanetary discs study, star forming regions, galaxies radial profiles, and high angular resolution measurements of the Sunyaev Zel'dovich (SZ) effect with the investigation of the morphology of galaxy cluster and the search for the Cosmic Web.