A. Monfardini

High angular resolution Sunyaev-Zel'dovich observations of MACS J1423.8+2404 with NIKA: Multiwavelength analysis

NIKA, the prototype of the NIKA2 camera, is an instrument operating at the IRAM 30m telescope that can observe the sky simultaneously at 150 and 260GHz. One of the main goals of NIKA is to measure the pressure distribution in galaxy clusters at high angular resolution using the Sunyaev-Zeldovich (SZ) effect. Such observations have already proved to be an excellent probe of cluster pressure distributions even at high redshifts. However, an important fraction of clusters host submm and/or radio point sources that can significantly affect the reconstructed signal. Here we report <20arcsec angular resolution observations at 150 and 260GHz of the cluster MACSJ1424, which hosts both radio and submm point sources. We examine the morphological distribution of the SZ signal and compare it to other datasets. The NIKA data are combined with Herschel satellite data to study the SED of the submm point source contaminants. We then perform a joint reconstruction of the ICM electronic pressure and density by combining NIKA, Planck, XMM-Newton and Chandra data, focussing on the impact of the radio and submm sources on the reconstructed pressure profile. We find that the large-scale pressure distribution is unaffected by the point sources due to the resolved nature of the NIKA observations. The reconstructed pressure in the inner region is slightly higher when the contribution of point sources are removed. We show that it is not possible to set strong constraints on the central pressure distribution without removing accurately these contaminants. The comparison with Xray only data shows good agreement for the pressure, temperature and entropy profiles, all indicating that MACSJ1424 is a dynamically relaxed cool core system. The present observations illustrate the possibility of measuring these quantities with a relatively small integration time, even at high redshift and without Xray spectroscopy.

A fast, ultra-sensitive and scalable detection platform based on superconducting resonators for fundamental condensed-matter and astronomical measurements

Low‐temperature physics and astronomy have traditionally focused on developing exquisitely sensitive single‐pixel detectors. While this has yielded considerable results, these technologies almost uniformly suffer from an inability to scale to large array sizes. In order to circumvent this barrier, frequency‐multiplexing techniques have recently emerged as a suitable solution. Here we present a detailed description of a measurement platform based on frequency‐multiplexed superconducting resonators along with the results from two distinct measurements that leverage this nascent technology to achieve multiple‐device readout. The first application discussed is a seven‐pixel array sensor of the permittivity of liquid helium suitable for quantum hydrodynamic experiments. The second implementation described is a prototype 16‐channel mm‐wavelength detector optimized for ground‐based astronomical detection at the 30 meter Institute for Millimeter‐Wave Radio Astronomy (IRAM) telescope in Pico Veleta, Spain.

Characterization and physical explanation of energetic particles on Planck HFI instrument

The Planck High Frequency Instrument (HFI) has been surveying the sky continuously from the second Lagrangian point (L2) between August 2009 and January 2012. It operates with 52 high impedance bolometers cooled at 100xa0mK in a range of frequency between 100xa0GHz and 1xa0THz with unprecedented sensitivity, but strong coupling with cosmic radiation. At L2, the particle flux is about 5

Mapping the kinetic Sunyaev-Zel'dovich effect toward MACS J0717.5+3745 with NIKA

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A multi-instrument non-parametric reconstruction of the electron pressure profile in the galaxy cluster CLJ1226.9+3332

cm-2s-1 and is dominated by protons incident on the spacecraft. Protons with an energy above 40xa0MeV can penetrate the focal plane unit box causing two different effects: glitches in the raw data from direct interaction of cosmic rays with detectors (producing a data loss of about 15xa0% at the end of the mission) and thermal drifts in the bolometer plate at 100xa0mK adding non-Gaussian noise at frequencies below 0.1xa0Hz. The HFI consortium has made strong efforts in order to correct for this effect on the time ordered data and final Planck maps. This work intends to give a view of the physical explanation of the glitches observed in the HFI instrument in-flight. To reach this goal, we performed several ground-based experiments using protons and

AMICA, an astro-mapper for AMS

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