Power spectrum of the cosmic infrared background at 60 and 100 $\mu$m with IRAS
M. A. Miville-Deschênes, G. Lagache, J. L. Puget;
AaA, 2002, 393, 749
ABSTRACT:Based on a power spectrum analysis of the IRAS ISSA maps, we present the first detection of the Cosmic far-Infrared Background (CIB) fluctuations
at 60 and 100 ~mp.
The power spectrum of 12 low cirrus emission regions is
characterized by a power excess at spatial frequencies higher than k ~ 0.02
arcmin-1.
Most of this excess is due to noise and to nearby point sources with a flux
stronger than 1 Jy.
But we show that when these contributions are carefully
removed, there is still a power excess that is the signature of the CIB
fluctuations.
The power spectrum of the CIB at 60 and 100 ~m is compatible with a Poissonian
distribution, at spatial frequencies between 0.025 and 0.2
arcmin-1.
The fluctuation level is ~ 1.6*E3 Jy2/sr and ~
5.8*E3 Jy2/sr at 60 and 100 ~m respectively.
The levels of the
fluctuations are used in a larger framework, with other observationnal data, to
constrain the evolution of IR galaxies (Lagache et al.
2002).
The detections
reported here, coupled with the level of the fluctuations at 170 mu m, give strong
constraints on the evolution of the IR luminosity function.
The combined results
at 60, 100 and 170 mu m for the CIB and its fluctuations allows, on the CIB at
60 mu m, to put a firm upper limit of 0.27 MJy/sr and to give an estimate of
0.18 MJy/sr.
Figures A.1 to A.9 are only available in electronic form at
http://www.edpsciences.org
KEYWORDS: cosmology: diffuse radiation, infrared: ism, infrared: general
PERSOKEY:statistical analysis, fir, iras, component separation, cib, ,
CODE: miville-deschenes2002b