Astron. Astrophys. 334, 420-426 (1998)

Correlation properties of the diffuse light from COBE -FIRAS maps

C. Burigana ¹ and L. Popa <sup>1, 2

1</sup> Istituto TeSRE, Consiglio Nazionale delle Ricerche, Via Gobetti 101, I-40129 Bologna, Italy
² Institute of Space Sciences, R-76900 Bucharest-Magurele, Romania

Received 11 August 1997 / Accepted 2 March 1998

Abstract

We search for a cosmic component of the far-infrared and submillimetre background using the data from the COBE-FIRAS instrument. From the correlation properties of the diffuse light maps obtained after all the foregrounds and discrete source contributions have been removed, we claim that the rms brightness is given by for m. At angular scales ranging from few degrees to few tens of degrees we find a steepening of the angular autocorrelation function with respect to the behaviour derived from galaxy surveys at smaller angular scales, becaming its spectral index , in agreement with the indications inferred from galaxy catalogues at similar scales. In addition it is found that the genus distributions of the diffuse light maps are consistent with a random gaussian field with a coherence angle , in agreement with COBE-DMR. These evidences support the extragalactic origin of the detected residual far-infrared background.

Key words: cosmic microwave background large-scale-structure of Universe diffuse radiation infrared: galaxies

Contents

• 1. Introduction
• 2. Theoretical preliminaries
• 3. Data analysis
  • 3.1. Foregrounds removal
  • 3.2. Properties of the residual component
• 4. Results
  • 4.1. Correlation properties of the diffuse light
  • 4.2. On the angular autocorrelation function
• 5. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: May 15, 1998

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