Open AccessExtragalactic source counts and contributions to the anisotropies of the cosmic microwave background: predictions for the Planck Surveyor mission
Author(s) -
L. Toffolatti,
F. Gómez,
G. de Zotti,
P. Mazzei,
A. Franceschini,
L. Danese,
C. Burigana
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01458.x
Subject(s) - physics , planck , cosmic microwave background , astrophysics , cosmic background radiation , source counts , noise (video) , extragalactic background light , astronomy , point source , spectral density , flux (metallurgy) , anisotropy , redshift , galaxy , optics , statistics , materials science , mathematics , artificial intelligence , computer science , metallurgy , image (mathematics)
We present predictions for the counts of extragalactic sources, the contributions to fluctuations and their angular power spectrum in each channel foreseen for the Planck Surveyor (formerly COBRAS/SAMBA ) mission. The contribution to fluctuations owing to clustering of both radio and far‐IR sources is found to be generally small in comparison with the Poisson term; however the relative importance of the clustering contribution increases and may eventually become dominant if sources are identified and subtracted down to faint flux limits. The central Planck frequency bands are expected to be ‘clean’: at high galactic latitude (| b | > 20°), where the reduced galactic noise does not prevent the detection of the extragalactic signal, only a tiny fraction of pixels is found to be contaminated by discrete extragalactic sources. Moreover, the ‘flat’ angular power spectrum of fluctuations resulting from extragalactic sources substantially differs from that of primordial fluctuations; therefore, the removal of contaminating signals is eased even at frequencies where point sources give a sizeable contribution to the foreground noise.