Absolute reference for microwave polarization experiments -- The COSMOCal project and its proof of concept
A Ritacco
(1)
,
L Bizzarri
(1)
,
S Savorgnano
(2)
,
F Boulanger
(3)
,
M Pérault
(1)
,
J Treuttel
(4)
,
P Morfin
(1)
,
A Catalano
(2)
,
D Darson
(1)
,
N Ponthieu
(5)
,
Bruno Maffei
(6)
,
A Feret
(4)
,
A Chahadih
(6)
,
G Pisano
(7)
,
M Zannoni
(8)
,
F Nati
(8)
,
J.F Macías-Pérez
(2)
,
A Monfardini
(9)
,
M Calvo
(10)
,
M Murgia
(11)
,
P Ortu
(11)
,
T Pisanu
(11)
,
J Aumont
(12)
,
J Errard
(13)
,
S Leclercq
(14)
,
M Migliaccio
(15)
1
LPENS -
Laboratoire de physique de l'ENS - ENS Paris
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 Astrophysique
4 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres
5 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
6 IAS - Institut d'astrophysique spatiale
7 UNIROMA - Università degli Studi di Roma "La Sapienza" = Sapienza University [Rome]
8 UNIMIB - Università degli Studi di Milano-Bicocca = University of Milano-Bicocca
9 NEEL - HELFA - Hélium : du fondamental aux applications
10 NEEL - Cryo - Cryogénie
11 OAC - INAF - Osservatorio Astronomico di Cagliari
12 CNES - Centre National d'Études Spatiales [Toulouse]
13 APC (UMR_7164) - AstroParticule et Cosmologie
14 IRAM - Institut de RadioAstronomie Millimétrique
15 Università degli Studi di Roma Tor Vergata [Roma, Italia] = University of Rome Tor Vergata [Rome, Italy] = Université de Rome Tor Vergata [Rome, Italie]
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 Astrophysique
4 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres
5 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
6 IAS - Institut d'astrophysique spatiale
7 UNIROMA - Università degli Studi di Roma "La Sapienza" = Sapienza University [Rome]
8 UNIMIB - Università degli Studi di Milano-Bicocca = University of Milano-Bicocca
9 NEEL - HELFA - Hélium : du fondamental aux applications
10 NEEL - Cryo - Cryogénie
11 OAC - INAF - Osservatorio Astronomico di Cagliari
12 CNES - Centre National d'Études Spatiales [Toulouse]
13 APC (UMR_7164) - AstroParticule et Cosmologie
14 IRAM - Institut de RadioAstronomie Millimétrique
15 Università degli Studi di Roma Tor Vergata [Roma, Italia] = University of Rome Tor Vergata [Rome, Italy] = Université de Rome Tor Vergata [Rome, Italie]
Résumé
The cosmic microwave background (CMB), a remnant of the Big Bang, provides unparalleled insights into the primordial universe, its energy content, and the origin of cosmic structures. The success of forthcoming terrestrial and space experiments hinges on meticulously calibrated data. Specifically, the ability to achieve an absolute calibration of the polarization angles with a precision of < 0.1 deg is crucial to identify the signatures of primordial gravitational waves and cosmic birefringence within the CMB polarization. We introduce the COSMOCal project, designed to deploy a polarized source in space for calibrating microwave frequency observations. The project aims to integrate microwave polarization observations from small and large telescopes, ground-based and in space, into a unified scale, enhancing the effectiveness of each observatory and allowing robust combination of data. To demonstrate the feasibility and confirm the observational approach of our project, we developed a prototype instrument that operates in the atmospheric window centered at 260 GHz, specifically tailored for use with the NIKA2 camera at the IRAM 30 m telescope. We present the instrument components and their laboratory characterization. The results of tests performed with the fully assembled prototype using a KIDs-based instrument, similar concept of NIKA2, are also reported. This study paves the way for an observing campaign using the IRAM 30m telescope and contributes to the development of a space-based instrument.