1999/02/24 by L. Toffolatti, G. de Zotti, Toffolatti, L. +6
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Radio Astronomy Observations and Technology #Superconducting and THz Device Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9902343
20 pages, LaTex (use paspconf.sty, epsf.sty), 5 EPS figures. Review talk at the Workshop "The Sloan Summit on Microwave Foregrounds", Princeton, NJ, 14-15 November 1998. Correct Journal-ref given: Invited review in "Microwave Foregrounds", eds. A. de Oliveira-Costa and M. Tegmark (ASP, San Francisco, 1999)
openalex publication_date 1999/02/24 · arxiv created 1999/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Confusion noise due to extragalactic sources is a fundamental astrophysical limitation for experiments aimed at accurately determining the power spectrum of the Cosmic Microwave Background (CMB) down to arcmin angular scales and with a sensitivity ΔT/T ≃ 10-6. At frequencies \lsim 200-300 GHz, the most relevant extragalactic foreground hampering the detection of intrinsic CMB anisotropies is constituted by radio loud Active Galactic Nuclei (AGN), including ``flat--spectrum'' radiogalaxies, quasars, BL-LACs and blazars. We review our present understanding of astrophysical properties, spectra, and number counts of the above classes of sources. We also study the angular power spectrum of fluctuations due both to Poisson distributed and clustered radio sources and give preliminary predictions on the power spectrum of their polarized components. Furthermore, we discuss the capabilities of future space missions (NASA's MAP, Bennett et al. 1995; ESA's Planck Surveyor, Bersanelli et al. 1996) in studying bright radio sources over an almost unexplored frequency interval where spectral signatures, essential for the understanding of the physical processes, show up.