Silvia Masi

Baffling and shielding system for a millimeter-wave balloonborne telescope

We describe a balloonborne telescope devoted to millimeter observations of diffuse sky radiation and optimized with a custom set of baffles and shields. The basic idea of the shield design is to shape the surfaces as roof mirrors to redirect the stray radiation in the opposite direction of incidence. The baffles are used to stop radiation close to the field of view. In this way we are able to avoid most of the unwanted radiation. We successfully operated this telescope (ARGO) during two flights, in 1989 and 1993, while detecting the faint structures of the cosmic microwave background at degree scale.

Precision measurements of the cosmic microwave background

Precision measurements of the Cosmic Microwave Background (CMB) sample the entire history of the Universe. In this paper we give a short review, from the experimentalist point of view, of the current status and of what can still be done, using this extraordinary tool, to investigate cosmology and fundamental physics.

Intergalactic Dust as Seen in Emission

Gerard and Antoinette de Vaucouleurs together with H. G. Corwin (1972), as well as Takase (1972), put forth the problem of intergalactic extinction within our Supergalaxy (sometimes called the Local Supercluster), and thus the problem of the existence of significant amounts of intergalactic dust in large agglomerations of galaxies. The problem is by no means an easy one. The very method of reducing photometric measurements can directly influence the results (see Gula et al. 1975 and Rudnicki 1986). On the other hand, it is not possible to correctly reduce the measurements without knowing intergalactic extinction parameters. This indeed seems to be a kind of vicious circle. Even if one does not consider it to be so, any data on intergalactic dust obtained by means other than investigation of extinction due to the dust, are of substantial importance for the problem.

Visual light and infrared observations as complementary sources of data on intergalactic dust

The significance of investigations of intergalactic dust in absorption, as well as of complementary observations in emission, is discussed. Infrared observations, particularly interesting for the Okroy Cloud, are cited. A program for further investigations is suggested.