Paolo de Bernardis et Andrew Lange

Italie - États-Unis

Prix Balzan 2006 pour l'astronomie et l'astrophysique observationnelles

Projet de recherche 

An Experimental Investigation of the First Stages of the Formation of Cosmic Structures

Paolo de Bernardis is Professor of Astrophysics and Observational Cosmology at the Università di Roma “La Sapienza”. Andrew Lange† was Marvin L. Goldberger Professor of Physics at the California Institute of Technology.
This project, carried out under Professor Paolo de Bernardis, aimed to measure the effect of the first structures on the background CMB light. This project uses an original approach: performing spectroscopic measurements of CMB anisotropy. From the experimental point of view, this strategy requires building a differential spectrometer matched to a large aperture telescope to achieve the necessary angular resolution. A long preparation text was needed to qualify the method. Technical publications analyzing possible systematic effects related to these measurements can be cited, and several more are in preparation. The first opportunity to test this idea experimentally will be with the forthcoming flight of the OLIMPO balloon-borne telescope, recently upgraded with an ambient-temperature differential spectrometer, which can be inserted as a plug-in in the optical path between the telescope and the multi-band photometer, transforming the 4-band photometer in a low-resolution spectrometer.
A full phase-A study of an innovative satellite mission, called SAGACE, carried out by the group at “La Sapienza” in the framework of the second project above has been completed. The full study has been described in a long document (ref. KISAGRP-010), which has been submitted to the Italian Space Agency for evaluation and possible implementation as a national small mission.
Balzan funds were used to acquire hardware to design and complete the instruments, to support the dedicated work of postdoctoral students already trained on the BOOMERanG project, to support the collaboration with the Cardiff (Ade, Mauskopf) and Pasadena (Lange) groups for the development of subsystems, and the diffusion of cosmology results through the preparation of a book on observational cosmology.
Three Balzan postdoctoral fellowships at “La Sapienza” focusing on the data analysis of the BOOMERanG and Planck experiments and on the SAGACE study have been assigned. This work resulted in a large number of papers. Balzan funds also provided support for: the hardware of the large throughput Martin-Puplett interferometer built in the group. This instrument is a prototype for the missions described above, and was the subject of the PhD thesis of Dr. Alessandro Schillaci; the development of innovative mm-wave detectors, the microwave kinetic inductance detectors (paper [16]) and the cold electron bolometers; cooperation with the Caltech group on CMB polarization measurements, with the development of a parallel study carried out in Europe for a space mission devoted to CMB polarization.
Two proposals have been submitted to ESA, with Paolo de Bernardis serving as the PI and the collaboration of the US teams in addition to the European ones. His group is also actively studying the impact of systematic effects on the scientific exploitation of these measurements. An even more ambitious mission, called PRISM, has been studied and proposed to ESA in 2013 in the framework of the call for science with large missions.

de Bernardis P et al. 2012. Low-resolution spectroscopy of the Sunyaev-Zeldovich effect and estimates of cluster parameters. Astronomy & Astrophysics. 538, A86.
Colafrancesco S, Marchegiani P, de Bernardis P, Masi S. 2013. A multi-frequency study of the SZE in giant radio galaxies. Astronomy and Astrophysics. 550, A92 (2013) astro-ph/1211.4809. DOI: 10.1051/0004-6361/201117376.
Schillaci A, de Bernardis P. 2011 On the effect of tilted roof reflectors in Martin-Puplett spectrometers. Infrared Physics. 55: 40-44.
Schillaci A, Battistelli E, D’Alessandro D, de Bernardis P, Masi S. 2013. On the emissivity of wire-grid polarizers for astronomical observations at mm-wavelengths. Infrared Physics & Technology. 58: 64–68.
de Bernardis P et al. 2012. SAGACE: the Spectroscopic Active Galaxies and Clusters Explorer. Proc. of the 12th Marcel Grossmann Meeting on General Relativity, Paris 12th-18th July 2009. Damour T, Jantzen RT, Ruffini R, editors. pp. 21-33. Singapore: World Scientific. ISBN-13 978-981-4374-51-4; astroph/1002.0867.
Planck Collaboration. 2011. Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster j candidates. A&A 536, A9.
Planck Collaboration. 2011. Planck early results. X. Statistical analysis of Sunyaev-Zeldovich scaling relations for X-ray galaxy clusters. A&A 536, A10.
Planck Collaboration. 2011. Planck early results. XI. Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations. A&A 536, A11.
Planck Collaboration. 2011. Planck early results. XII. Cluster Sunyaev-Zeldovich optical scaling relations Planck Collaboration. A&A 536, A12.
Tarasov Mikhail A, Kuzmin LS, Edelman VS, Mahashabde S, de Bernardis P. 2011. Optical Response of a Cold-Electron Bolometer Array Integrated in a 345-GHz Cross-Slot Antenna. IEEE Transactions on Applied Superconductivity. 21: 3635-3639.
Salatino M, de Bernardis P, Kuzmin LS, Masi S, Mahashabd S. Sensitivity to Cosmic Rays of Cold Electron Bolometers for Space Applications. 2013. Journal of Low Temperature Physics. Submitted 2013.
The COrE Collaboration. 2011. COrE (Cosmic Origins Explorer) A White Paper. astro-ph/1102.2181. Pagano L et al. 2009. CMB Polarization Systematics, Cosmological Birefringence and the Gravitational Waves Background. Physical Review. D80, 043522.
The PRISM collaboration. 2013. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky. astro-ph/ 1306.2259.

Excerpt from the: The Balzan Prizewinners’ Research Projects: An Overview 2016