Current Status and Perspectives of Cosmic Microwave Background Observations

Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are powerful observational objectives as they encode information on fundamental cosmological parameters and on the physics of the early universe. A large number of increasingly ambitious balloon-borne and ground-based experiments have been carried out following the first detection of CMB anisotropies by COBE-DMR, probing the angular power spectrum up to high multipoles. The recent data from WMAP provide a new major step forward in measurements percision. The ESA mission Planck Surveyor, to be launched in 2007, is the third-generation satellite devoted to CMB imaging. Planck is expected to extract the full cosmological information from temperature anisotropies and to open up new fronteers in the CMB field.Comment: 6 pages, 1 figure, to appear in "Proc of International Symposium on Plasmas in the Laboratory and in the Universe: new insights and new challenges", September 16-19, 2003, Como, Ital

Astrofisica, Cosmologia, Fisica Fondamentale e Fisica del Sistema Solare dallo Spazio: il contributo nazionale

Contributo dato nella primavera del 2019 al "Gruppo di Consulenza e Coordinamento, del Dipartimento per la Formazione Superiore e la Ricerca, per il Nuovo Piano Nazionale della Ricerca (PNR) per le Proposte e Strategie Nazionali e per Horizon Europee 2021-2027 (coordinato dai Prof. Giuseppe Valditara, Dott. Paolo Branchini e Prof. Andrea Lenzi)" Area 9: Space and Aeronautics coordinata dal Prof. Ezio Bussoletti.Il presente documento, di cui gli autori costituiscono il “Board editoriale”, presenta una sintesi delle attività del Paese nell'esplorazione del Sistema Solare e nell'osservazione dell’Universo effettuate dallo Spazio. I dati citati sono estratti principalmente dal Piano Triennale e dal Documento di Vision dell’Istituto Nazionale di Astrofisica (INAF), predisposti attraverso protocolli di consultazione con gli organismi e le articolazioni dell’Ente, e con un ampio coinvolgimento di tutta la comunità di riferimento in campo spaziale (si stima circa 1500 ricercatori fra INAF, che di norma è capofila delle iniziative, e svariati altri Enti di Ricerca e Università)

Optimisation of Edge Taper values for the 70 GHz LFI Feed Horns

Scope of this technical note is to assess new edge taper requirements for the LFI 70 GHz channel. The aim is to improve the angular resolution of the LFI 70 GHz beams maintaining the Galactic Straylight Induced Noise (SIN) at a level lower than 3 μk peak to peak. For the baseline dual profiled corrugated feed horn #23 (PG26 − QM) the 4π antenna pattern has been computed using GRASP8 MrGTD and the corresponding Galactic SIN introduced by most relevant Galactic foreground components has been evaluated through astrophysical simulations. Then, the Edge Taper (ET) of this horn has been degraded in order to improve the angular resolution; the corresponding Galactic SIN has been extrapolated by the results of the detailed study carried out on the LFI #9 at 100 GHz. The same extrapolation has been assumed for the 70 GHz feed horns #22 and #21

Optimisation of the LFI Edge Taper values. I. FH #3 and #9 Main Beam and Full Pattern Simulations w/o Shields

This technical note describes preliminary electromagnetic simulations performed on the LFI feed horns (FH) #3 and #9 coupled to the Planck telescope, with the aim of optimising the LFI Edge Taper (ET). The ET optimisation is mandatory to reach the LFI angular resolution requirement, and possibly the goal, preserving at the same time the needed straylight rejection. The analysis is carried out at 100 GHz, where the scientific benefit of gaining angular resolution is most important. Five different FH designs have been considered: the FH #3 and #9 Qualification Model (QM) designs, and FH designs denoted with #3A, #9A, and #9B, which have been specifically designed with an edge taper that leads to an angular resolution of 12’, 10’, and 9.5’, respectively, when Gaussian feed models are considered. For FH horn design the main beam and the full pattern have been computed. The effect of shields has not been considered here, and will be the subject of a forthcoming note

Thermal stability in precision cosmology experiments: the Planck LFI case

Abstract After the great success of NASA's satellite missions COBE and WMAP, the Planck mission represents the third generation of mm-wave instruments designed for space observations of CMB anisotropies. Two instruments, the LowFrequency Instrument (LFI) and the High-Frequency Instrument (HFI) will produce CMB maps with unprecedented angular resolution, sensitivity and frequency coverage. This ambitious task will be achieved by using low noise HEMT detectors cryogenically cooled at B20 K for the LFI and bolometric detectors cooled at 0.1 K for the HFI; in particular, the LFI is based on pseudo-correlation receivers in which the sky signal is continuously compared to a cryogenic reference load in thermal contact with the HFI 4 K stage. Such high sensitivity in Planck detectors calls for a strict control of systematic effects, which must be kept at mK level in the final maps; this in turn imposes tight requirements on the thermal and electrical stability of the different stages in the instrument. In this paper we discuss a study of the impact of thermal fluctuations at the level of the 20 K cooler cold-end on the Planck-LFI measurements and present some viable solutions that have been adopted to keep the residual systematic error within the required values for Planck-LFI.

In-flight calibration and verification of the Planck-LFI instrument

In this paper we discuss the Planck-LFI in-flight calibration campaign. After a brief overview of the ground test campaigns, we describe in detail the calibration and performance verification (CPV) phase, carried out in space during and just after the cool-down of LFI. We discuss in detail the functionality verification, the tuning of the front-end and warm electronics, the preliminary performance assessment and the thermal susceptibility tests. The logic, sequence, goals and results of the in-flight tests are discussed. All the calibration activities were successfully carried out and the instrument response was comparable to the one observed on ground. For some channels the in-flight tuning activity allowed us to improve significantly the noise performance.Comment: Long technical paper on Planck LFI in flight calibration campaign: 109 pages in this (not final) version, 100 page in the final JINST versio

Treatment Outcome of metastatic lesions from renal cell carcinoma underGoing Extra-cranial stereotactic body radioTHERapy: The together retrospective study

Abstract Objectives stereotactic body radiation therapy (SBRT) use has increased overtime for the management of metastatic renal cell carcinoma (mRCC) patients, with a likely good control of irradiated lesions. We planned a retrospective multicenter Italian study, with the aim of investigating the outcome of treatment with SBRT for non-brain secondary lesions in mRCC patients. Methods all consecutive metastatic non-brain lesions from mRCC that underwent SBRT at nine Italian institutions from January 2015 to June 2017 were considered. The primary endpoint of the study was the lesion-PFS, calculated from SBRT initiation to the local progression of the irradiated lesion. Results 57 extracranial metastatic lesions from 48 patients with primary mRCC were treated with SBRT. At the median follow-up of 26.4 months, the median lesion-PFS was not reached (43 censored); 72.4% of lesions were progression-free at 40 months, with significantly better lesion-PFS for small metastatic lesions ( Conclusions consistently with the previous literature, our findings support the use of SBRT in selected mRCC patients