University of Rome “La Sapienza” - Department of Physics Piazzale A. Moro, 2 – 00185 Rome, Italy

CASPER

(Concordia Atmospheric SPectroscopy of Emitted Radiation)

Spectrometer devoted to measurements of atmospheric emission in the spectral region between 180 microns and 3 mm (3÷55cm-1) proposed to be installed at Dome C in Antarctica at Concordia Italian-french base.

CASPER2

The existing instrument version designed to explore a more limited spectral region (90÷450 GHz or 3÷15cm−1) is already developed and it has operated successfully in the Alps co-aligned with the optical axis of the 2.6-m in diameter telescope of MITO (Millimetre and Infrared Testagrigia Observatory, Italy).

Department of Physics University La Sapienza Rome ITALY

M. De Petris (PI)

D. Buzi

S. De Gregori

L. Lamagna

Collaborators & Supporters

Department of Physics Milan Bicocca University Milan ITALY

M. Zannoni

A. Baù

A. Passerini

Institute of Atmospheric Sciences and Climate – CNR Bologna ITALY

S. Masieri

C. Tomasi

B. Petkov

Astroparticule et Cosmologie, Université Denis Diderot - Paris 7 Paris FRANCE

J.C. Hamilton

J.M: Piat

Dpt of Physics and Astronomy University College London London UK

G. Savini

School of Physics and Astronomy Cardiff University Cardiff (UK)

G. Pisano

C. Tucker

News

A modified version of CASPER2 is scheduled to be installed at Concordia Station (Dome C) from December 11, 2014 to February 4, 2015.

Follow CASPER Expedition in Antarctica on

Instrument concept

CASPER2 is composed of a:

· 2-mirrors telescope f/3.5 Pressman-Camichel configuration [62-cm concave spherical primary mirror (Officine Ottico Meccaniche Marcon) with a 12-cm convex ellipsoidal subreflector (INFN machine workshop Department of Physics in Rome)], telescope shield with vanes; subreflector support in styrodur. · Interferometer a Martin-Puplett interferometer with 3 different kinds of phase modulations: 1- amplitude modulation (AM), 2- fast-scan (FS) and 3 - phase modulation (PM). · wet cryostat two liquid nitrogen and helium tanks and a He3 fridge (Infrared Labs, HDL-8) cool down to 290 mK two Ge-bolometers. · altazimuthal mount the telescope control is realized with Magellano ST7 (ATEC Robotics) and a CCD camera (SBIG, ST-402ME) is employed as star-tracker.

2-mirror telescope

Interferometer

wet cryostat

altazimuthal mount

Preliminary observations of CASPER2 were performed at MITO, with logistical support provided by Sezione IFSI/INAF di Torino, now Osservatorio Astrofisico di Torino.

Sunrise at MITO

Relevant papers

“Atmospheric monitoring in the mm and sub-mm bands for cosmological observations: CASPER2”

De Petris M., De Gregori S., B. Decina, L. Lamagna and J.R. Pardo.

Monthly Notices of the Royal Astronomical Society, 425, 222–230 (2012)

doi:10.1111/j.1365-2966.2012.21430.x arXiv:1211.2929v1

“Millimetre and submillimetre atmospheric performance at Dome C combining radiosoundings and ATM synthetic spectra”

De Gregori S., M. De Petris, B. Decina, L. Lamagna, J.R. Pardo, B. Petkov, C. Tomasi and L. Valenziano

Monthly Notices of the Royal Astronomical Society, Volume 425, Issue 222 (2012)

doi:10.1111/j.1365-2966.2012.21430.x ,arXiv:1204.0975v2

“Site-testing and continuous atmospheric monitoring at mm wavelength band with CASPER2”

Decina B., S. De Gregori, M. De Petris and L. Lamagna

EAS Publications Series Volume 40, (2010) 3rd ARENA Conference on "An Astronomical Observatory at CONCORDIA (Dome C, Antarctica)"

“CASPER: Concordia Atmospheric SPectroscopy of Emitted Radiation”

De Petris M., A. Catalano, S. De Gregori, L. Lamagna, V. Lattanzi, G. Luzzi, R. Maoli, A. Melchiorri, F. Melchiorri, G. Savini, G. G. Vetrani, E.S. Battistelli, L. Valenziano, N. Mandolesi, F. Villa, F. Cuttaia, P.A.R. Ade, Mauskopf, A. Orlando, P. Encrenaz, J.R. Pardo and J. Cernicharo

“Dome C Astronomy and Astrophysics Meeting” Toulose July 2004 M.Giard, F.Casoli and F.Paletou (eds) EAS Publications Series, 14 (2005) 233-238

Related links

Gruppo di Cosmologia Sperimentale G31

· G31_page

Millimetre & Infrared Testa grigia Observatory

· MITO_page

Last update July, 2014 - Page Editor MDP