G. Guarini et al., INFLUENCE OF GALACTIC DUST ON THE ACCURACY OF COSMIC MICROWAVE ANISOTROPY MEASUREMENTS, The Astrophysical journal, 442(1), 1995, pp. 23-29
We have derived the power spectrum of Galactic dust emission by simula
ting cosmic background experiments on IRAS maps. We have found that th
e power index depends on the amount of dust, ranging from -3 (moderate
ly clean regions, like the north celestial pole) down to -2 (the Lockm
an Hole) or less (the cleanest regions, in the southern hemisphere). T
herefore, for very low backgrounds, like those found in the cleanest d
ust regions, the spurious anisotropies produced by dust tend to decrea
se with the beam size, up to 10 degrees-20 degrees. For larger angular
scales, the Galactic noise increases again. For moderate backgrounds,
the spurious anisotropies have a flat spectrum or increase with the b
eam size. These results have been used to design an optimized cosmic b
ackground radiation (CBR) experiment in the far-infrared. Significant
contamination in CBR anisotropy measurements is expected for wavelengt
hs shorter than 1 mm, at both small and large angular scales. A cleani
ng technique is suggested based on the use of a ground telescope opera
ting through the millimetric atmospheric windows with an angular resol
ution of similar to 5'.