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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f01.ps}\end{figure}$ Figure 1: Sensitivity to the bolometric luminosity (and star formation rate, assuming star forming galaxies) of various infrared and submillimeter experiments. Detections of at least 10 sources in the surveys can be made in the areas above the curves. We assumed the scenario of a typical deep survey. ISOCAM 15 $\mu$ m ( $S_{\nu} > 250~\mu$ Jy, 2 Sq. Deg.); ISOPHOT 170 $\mu$ m ( $S_{\nu } > 180$ mJy, 5 Sq. Deg.); Spitzer/MIPS 24 $\mu$ m ( $S_{\nu} > 80~\mu$ Jy, 5 Sq. Deg.); Spitzer/MIPS 70 $\mu$ m ( $S_{\nu } > 25$ mJy, 5 Sq. Deg.); Spitzer/MIPS 160 $\mu$ m ( $S_{\nu } > 50$ mJy, 5 Sq. Deg.); SCUBA 850 $\mu$ m ( $S_{\nu } > 1$ mJy, 1 Sq. Deg.); This plot makes use of the Lagache et al. (2004) model and their starburst SED for the conversion to $L_{\rm bol}$ . At $z \sim 1$ , MIPS detects only ULIRGs in the FIR, and detects LIRGs in the MIR. The stacking analysis allows to gain an order of magnitude and to probe LIRGs in the FIR.
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In the text

$\begin{figure} \par\includegraphics[width=7.2cm,clip]{4446f02.ps} \end{figure}$ Figure 2: Images at 24, 70 and 160 $\mu$ m ( left to right) of stacked sources in the brightest bin of 24 $\mu$ m flux density, with a random position offset added before each sum. Color coding: dark is high flux, light is low flux. This allows us to check that the stacking method does not introduce any artifacts, i.e. a false source detection in the center.
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In the text

$\begin{figure} \par\includegraphics[width=6.6cm,clip]{4446f03.ps} \end{figure}$ Figure 3: Images at 24 $\mu$ m of stacked sources in bins of 24 $\mu$ m flux density ( $S_{24} \ge 60~\mu$ Jy) in the three MIPS GTO Fields: CDFS, HDFN, and LH covering about 0.85 Sq. Deg. A total number of 19181 sources has been used. The number of sources used in the sum in each S₂₄ bin is reported. Each image has $350 \times 350$ pixels of 1.25 arcsec, thus covering about $7.3 \times 7.3$ Sq. Arcmin. Since no outlier rejection has been made, other sources can be seen in the surroundings of the stacked sources.
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In the text

$\begin{figure} \par\includegraphics[width=6.6cm,clip]{4446f04.ps} \end{figure}$ Figure 4: Images at 70 $\mu$ m of stacked sources in bins of 24 $\mu$ m flux density. See caption of Fig. 3 for details.
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In the text

$\begin{figure} \par\includegraphics[width=6.6cm,clip]{4446f05.ps} \end{figure}$ Figure 5: Images at 160 $\mu$ m of stacked sources in bins of 24 $\mu$ m flux density. See caption of Fig. 3 for details.
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In the text

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{4446f06a.ps}\vspace*{2mm} \includegraphics[width=7.7cm,clip]{4446f06b.ps} \end{figure}$ Figure 6: Normalized radial profiles of the stacked images. The crosses represent the data, and the solid line the empirical PSF. The vertical dotted lines show the radii of the aperture used for photometry. From top to bottom: faintest S₂₄ bin at 70 $\mu$ m; brightest S₂₄ bin at 70 $\mu$ m; faintest S₂₄ bin at 160 $\mu$ m; brightest S₂₄ bin at 160 $\mu$ m.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{4446f07.ps} \end{figure}$ Figure 7: Top: confidence Level of the detections at 70 (dash) and 160 $\mu$ m (solid) on stacked images (Figs. 4 and 5), as a function of the S₂₄ bin. Middle: Signal-to-Noise ratio, as computed from a Gaussian fit to the flux distribution measured on about 2000 positions; this S/N is not relevant at low flux (see Sect. 3.2). Bottom: average flux in mJy per stacked source. Note that a different number of sources have been stacked in each bin.
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In the text

$\begin{figure} \par\includegraphics[width=7.9cm,clip]{4446f08.ps}\end{figure}$ Figure 8: Contributions to the CIB: brightness of stacked sources at 160 and 70 $\mu$ m per logarithmic bin $\frac{{\rm d}B_{\lambda}}{{\rm d}\log(S_{24})}$ (solid symbols), as a function of the 24 $\mu$ m flux, in all three MIPS GTO Fields. A completeness correction has been applied. The highest flux bin goes up to 1 Jy. Open symbols: published differential source counts multiplied by S₂₄^-0.5 and a color ratio of bright galaxies (160/24 = 60 and 70/24 = 20, cf. the brightest bin in the lower panel of Fig. 7); Square: Dole et al. (2004a); Circle: Frayer et al. (2006). There is a good agreement between the source counts, the brightest stacked bin, and the fainter stacked bins.
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In the text

$\begin{figure} \par\includegraphics[width=14.4cm,clip]{4446f09.ps} \end{figure}$ Figure 9: Current measurements of the Extragalactic Background Light Spectral Energy Distribution from 0.1 $\mu$ m to 1 mm, showing the Cosmic Optical Background (COB, with $\lambda \le 8~\mu$ m) and the Cosmic Infrared Background (CIB, with $\lambda > 8~\mu$ m). Black arrows represent lower limits. Purple arrows and lines represent upper limits. The EBL observational constraints come from: Edelstein et al. (2000) at 0.1 $\mu$ m using Voyager UVS; Brown et al. (2000) and Gardner et al. (2000) with HST/STIS (lower limits); Madau & Pozzetti (2000) with HST (incl. NICMOS) and Thompson (2003); Bernstein et al. (2002) corrected by Mattila (2003) (filled circles); Matsumoto et al. (2005) between 2.2 and 4 $\mu$ m using the IRTS (thin plus); Gorjian et al. (2000) at 2.2 and 3.3 $\mu$ m using DIRBE and Lick; Wright (2001) and Cambresy et al. (2001) at 1.25 and 2.2 $\mu$ m using DIRBE and 2MASS (five branch star); DIRBE values from Wright (2004) from 1.25 to 240 $\mu$ m (gray circles); Spitzer IRAC 3.6, 4.5, 5.8 and 8.0 $\mu$ m lower limits from number counts by Fazio et al. (2004); fluctuation analysis with IRAC by Savage & Oliver (2005) (open triangles); Schroedter (2005) using Very High Energy Blazars, 98% confidence upper limit (gray region); HESS upper limit from Aharonian et al. (2005) using P0.55 (solid line between 0.8 and 4 $\mu$ m); Renault et al. (2001) upper limits from 5 to 15 $\mu$ m using the CAT in the $\gamma$ -rays on Mkn501; Elbaz et al. (1999) lower limit at 15 $\mu$ m using galaxy counts with ISOCAM; upper limit at 20 $\mu$ m by Stecker & De Jager (1997) on Mkn421; lower limit from galaxy counts at 24 $\mu$ m with MIPS by Papovich et al. (2004); an indirect evaluation at 60 $\mu$ m using fluctuations in IRAS data from Miville-Deschênes et al. (2002) (open gray square); lower limits at 70 and 160 $\mu$ m using galaxy counts with MIPS by Dole et al. (2004a); an estimate of the CIB at 100 $\mu$ m using CAT and DIRBE Renault et al. (2001) (four branch star); Lagache et al. (2000) at 100, 140 and 240 $\mu$ m using DIRBE and WHAM, updated in the present work (diamond); Hauser et al. (1998) at 140 and 240 $\mu$ m using DIRBE (open square); Smail et al. (2002) lower limit at 850 $\mu$ m using galaxy counts with SCUBA; Lagache et al. (2000) spectrum between 200 $\mu$ m and 1.2mm using FIRAS (solid line above 200 $\mu$ m). The IDL script to generate this figure is available on the web: http://www.ias.u-psud.fr/irgalaxies.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{4446f10.ps} \end{figure}$ Figure 10: Cumulative brightness ( left axis, in MJy/sr) and fraction of the background resolved ( right axis) at 160, 70 and 24 $\mu$ m ( from top to bottom), as a function of the 24 $\mu$ m flux in the three combined MIPS GTO Fields. A completeness correction has been applied based on the incompleteness level of the 24 $\mu$ m sample. The horizontal dashed line represents 50% of the CIB at each wavelength.
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In the text

$\begin{figure} \par\includegraphics[width=14.4cm,clip]{4446f11.ps} \end{figure}$ Figure 11: Extragalactic background light spectral energy distribution from 0.1 $\mu$ m to 1 mm, with new constraints from MIPS. The lowest lower limits (red) represent the fraction of the CIB resolved at 70 and 160 $\mu$ m using the stacking analysis for sources with $S_{24} \ge 60~\mu$ Jy. The large (blue) square represents the contribution of all the unresolved 24 $\mu$ m sources (extrapolation from number counts), and the highest lower limits arrows (blue) represent the contribution of all 24 $\mu$ m sources to the FIR background, using a simple color extrapolation for 70 and 160 $\mu$ m (Sect. 5). See Fig. 9 for the other symbols.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f12.ps} \end{figure}$ Figure 12: Cosmic Optical Background and Cosmic Infrared Background due to galaxies permitted zone estimate (shaded area), using upper and lower values. See Fig. 9 for the other symbols.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f13.ps} \end{figure}$ Figure 13: Our best Cosmic Optical Background (blue-shaded, left) and Cosmic Infrared Background (red-shaded, right) estimates. The gray-shaded area represents the region of overlap. See Fig. 9 for the other symbols.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f14.ps} \end{figure}$ Figure 14: Schematic Spectral Energy Distributions of the most important (by intensity) backgrounds in the universe, and their approximate brightness in nW m^-2 sr^-1 written in the boxes. From right to left: the Cosmic Microwave Background (CMB), the Cosmic Infrared Background (CIB) and the Cosmic Optical Background (COB).
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In the text

$\begin{figure} \par\includegraphics[width=7.2cm,clip]{4446f02.ps} \end{figure}$	Figure 2: Images at 24, 70 and 160 $\mu$ m ( left to right) of stacked sources in the brightest bin of 24 $\mu$ m flux density, with a random position offset added before each sum. Color coding: dark is high flux, light is low flux. This allows us to check that the stacking method does not introduce any artifacts, i.e. a false source detection in the center.
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$\begin{figure} \par\includegraphics[width=6.6cm,clip]{4446f04.ps} \end{figure}$	Figure 4: Images at 70 $\mu$ m of stacked sources in bins of 24 $\mu$ m flux density. See caption of Fig. 3 for details.
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$\begin{figure} \par\includegraphics[width=6.6cm,clip]{4446f05.ps} \end{figure}$	Figure 5: Images at 160 $\mu$ m of stacked sources in bins of 24 $\mu$ m flux density. See caption of Fig. 3 for details.
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$\begin{figure} \par\includegraphics[width=7.7cm,clip]{4446f06a.ps}\vspace*{2mm} \includegraphics[width=7.7cm,clip]{4446f06b.ps} \end{figure}$	Figure 6: Normalized radial profiles of the stacked images. The crosses represent the data, and the solid line the empirical PSF. The vertical dotted lines show the radii of the aperture used for photometry. From top to bottom: faintest S₂₄ bin at 70 $\mu$ m; brightest S₂₄ bin at 70 $\mu$ m; faintest S₂₄ bin at 160 $\mu$ m; brightest S₂₄ bin at 160 $\mu$ m.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f12.ps} \end{figure}$	Figure 12: Cosmic Optical Background and Cosmic Infrared Background due to galaxies permitted zone estimate (shaded area), using upper and lower values. See Fig. 9 for the other symbols.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f13.ps} \end{figure}$	Figure 13: Our best Cosmic Optical Background (blue-shaded, left) and Cosmic Infrared Background (red-shaded, right) estimates. The gray-shaded area represents the region of overlap. See Fig. 9 for the other symbols.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{4446f14.ps} \end{figure}$	Figure 14: Schematic Spectral Energy Distributions of the most important (by intensity) backgrounds in the universe, and their approximate brightness in nW m^-2 sr^-1 written in the boxes. From right to left: the Cosmic Microwave Background (CMB), the Cosmic Infrared Background (CIB) and the Cosmic Optical Background (COB).
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