OLIMPO is a long-duration balloon mission designed to study clusters of galaxies through the Sunyaev-Zel'dovich (SZ) effect. The payload is equipped with a differential Fourier Transform Spectrometer covering the spectral range from 120 to 500GHz in four frequency bands optimized to detect the SZ signal from clusters of galaxies. Thanks also to its 2.6m primary mirror, OLIMPO will be able to observe with high angular resolution the spectral region above 217GHz, where SZ effect produces a positive signal. This unique combination makes OLIMPO complementary to ground-based telescopes such as the South Pole Telescope and the Atacama Cosmology Telescope, that are sensitive only to the negative part of the SZ effect below 217GHz.

The extended frequency coverage of OLIMPO will also allow for accurate measurements of the Cosmic Microwave Background anisotropies and of the Cosmic Infrared Background produced by early galaxies, thus opening a new window on cosmic evolution of star-forming galaxies.

Such ambitious scientific program can be achieved only through a long duration circumpolar flight on a stratospheric balloon, which is currently planned for launch in June 2014 from Svalbard Islands.

Scientific Goals

OLIMPO is aiming to:
- measure the SZ effect from about 40 clusters of galaxies
- observe the CMB on angular scales from 5 degrees to 2 arcminutes
- detect the diffuse SZ signal coming from unresolved clusters
- characterize CIB anisotropies and evolution of star-forming galaxies

Italian Contribution

OLIMPO is an Italian programme supported by ASI and led by Silvia Masi of University of Rome "La Sapienza". International partnership is limited to some parts of the instrument. The Physics Dept. of University of Rome "La Sapienza" will also manage the launch thanks to a co-funded ASI contract.