AAS 207th Meeting, 8-12 January 2006
Session 100 Cosmology, Early Universe, Cosmic Distance Scale I
Oral, Tuesday, 2:00-3:30pm, January 10, 2006, Salon 1

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[100.01] The Near Infrared Background: Interplanetary Dust or Primordial Stars

E. Dwek (NASA Goddard Space Flight Center), R. G. Arendt (Science Systems and Applications, Inc.), F. Krennrich (Iowa State University)

The intensity of the diffuse ~ 1 - 4 \mum sky emission from which solar system and Galactic foregrounds have been subtracted is in excess of that expected from energy released by galaxies and stars that formed during the z \lesssim 6 redshift interval. The spectral signature of this excess near-infrared background light (NIRBL) component is almost identical to that of reflected sunlight from the interplanetary dust cloud, and could therefore be the result of the incomplete subtraction of this foreground emission component from the diffuse sky maps. Alternatively, this emission component could be extragalactic. Its spectral signature is consistent with that of redshifted continuum and recombination line emission from HII regions formed by the first generation of very massive stars (Population III stars). An extragalactic origin will have implication for the formation rate of these stars, the redshift interval during which they formed, the reionization of the universe and evolution of collapsed halo masses. Furthermore, an extragalactic origin for the NIRBL can leave an imprint of the TeV gamma-ray spectrum of blazars. In this presentation we discuss the results of our analysis, and their implications for the origin of the NIRBL. This research was funded by NASA LTSA-2003


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