On the ISW-cluster cross-correlation in future surveys

We investigate the cosmological information contained in the cross-correlation between the Integrated Sachs-Wolfe (ISW) of the Cosmic Microwave Background (CMB) anisotropy pattern and galaxy clusters from future wide surveys. Future surveys will provide cluster catalogues with a number of objects comparable with galaxy catalogues currently used for the detection of the ISW signal by cross-correlation with the CMB anisotropy pattern. By computing the angular power spectra of clusters and the corresponding cross-correlation with CMB, we perform a signal-to-noise ratio (SNR) analysis for the ISW detection as expected from the eROSITA and the Euclid space missions. We discuss the dependence of the SNR of the ISW-cluster cross-correlation on the specifications of the catalogues and on the reference cosmology. We forecast that the SNRs for ISW-cluster cross-correlation are alightly smaller compared to those which can be obtained from future galaxy surveys but the signal is expected to be detected at high significance, i.e. more than $> 3\,\sigma$. We also forecast the joint constraints on parameters of model extensions of the concordance $\Lambda$CDM cosmology by combining CMB and the ISW-cluster cross-correlation.Comment: 12 pages, 10 figures. Matches version accepted in MNRA

4KRL adhesive thermal cycle facility

This document will describe the cryo facility designed for sample thermal cycling

Attività di ‘packaging’ degli LNA all’interno del carrier, studiato per funzionare a temperature criogeniche

Il presente documento si inserisce nell’ambito delle attività svolte finalizzate allo studio e alla realizzazione di un prototipo di amplificatore criogenico a basso rumore in banda W, basato su tecnologia MMIC mHEMT. Il cuore del lavoro è l’attività di ‘packaging’ degli LNA all’interno del modulo (carrier), studiato per funzionare a temperature criogeniche. Tale attività ha evidenziato potenziali criticità che si desidera, attraverso questa nota tecnica, approfondire

The 4KRL cryo facility

Purpose of the Planck-LFI 4KRL is to provide a stable reference signal to the LFI radiometers. It is fully described in RD 1. Purpose of the instrument described in this note is to provide a test facility for the 4KRL unit. Purpose of this document is to describe the general characteristics and performance of this facility

Square Kilometre Array and cosmic microwave background spectral distortions

The Square Kilometre Array (SKA) is a new technology (large array) radio-telescope that, owing to its extremely high sensitivity and resolution, will allow to investigate different cosmological and astrophysical topics. In this work, we discuss the possible contribution of the SKA in combination with future cosmic microwave background experiments in probing various types of dissipation processes relevant at different cosmic epochs

PLANCK\LFI 4K Reference Load Test Plan

The purpose of this document is to describe the tests to be performed on the QM, FM, and FS 4KRL uni

A Refined Calibration Procedure of Two-Channel Sun Photometers to Measure Atmospheric Precipitable Water at Various Antarctic Sites

Abstract Two-channel sun photometers can be easily employed at Antarctic sites, where harsh environmental conditions prevail, to carry out measurements of precipitable water W. In the very dry air conditions observed in the Antarctic atmosphere, water vapor does not produce strong absorption features along the sun path. Therefore, these instruments need to be calibrated using analytical forms different from the square root regime, which can be determined by simulating the output voltages measured at Antarctic sites, for the spectral near-IR curves of extraterrestrial solar irradiance, instrumental responsivity parameters, and atmospheric transmittance, relative to various measurement periods. For this purpose, average models of the Antarctic atmosphere from the ground level up to the 30-km altitude were considered for different solar zenith angles and relative humidity conditions. The ratios between the output voltages simulated in the band and window channels were plotted as a function of total water vapor content Cw, for each site and each period, to define the best-fit calibration curves, which were subsequently normalized to the field measurements to take into account the aging effects on the filter transmission characteristics. Each of the five calibration curves was found to present a slope coefficient decreasing gradually with Cw from values higher than 0.8 to about 0.6. Using these curves, measurements of W were obtained, which differ appreciably at both sea level and high-altitude sites from those given by the square root calibration curves, avoiding large overestimation errors of 10%–40% at the high-altitude sites and underestimation errors of 5%–15% at the sea level site

Preliminary evaluation of the impact of temperature fluctuations in the HFI 4Kstage on LFI

In this technical note we provide a preliminary analysis of the effect of temperature fluctuations at the level of the HFI 4K stage on the scientific performances of the Planck-LFI instrument. The stability of this stage is of crucial importance for the LFI, as it impact directly the stability of the measured signal through its reference load. The availability of the first simulations of the 4K temperature stability from the HFI team has prompted a quick assessment of the expected effect, which is found to be large enough to require the application of software removal algorithms to maintain the residual effect in the final maps within the required levels. Clearly it is of crucial importance the availability in a short time of measurements from the HFI 4K cooler in order to be able to perform robust estimates of the final expected systematic effect

Temperature stability requirements at the interface between the ECCOSORB sky-load and its support in the LFI cryofacility

During the testing phase of the QM and FM LFI instrument, the integrated radiometer chain assemblies (RCAs) will be tested in a dedicated cryo facility. The input signal will be provided by an eccosorb load placed in front of the LFI feed horns that simulates the sky signal; the thermal stability of this sky load needs to be of the same order of the stability that is expected in flight for the primary and secondary mirrors, in order not to introduce uncertainties in the test results that may be difficult to interpret. In this document we derive the thermal stability requirements at the interface between the ECCOSORB sky load and its support starting from the signal stability requirements and considering the current knowledge concerning thermal conduction properties of the ECCOSORB at 20 K