|Annu. Rev. Astron. Astrophys. 2001. 39:
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4.5. Limit on Intergalactic Dust
Intergalactic dust, if sufficiently abundant, could give rise to a truly diffuse emission component of the CIB. The possible existence of intergalactic dust, and the consequences for determining the deceleration parameter of the universe, were first considered by Margolis & Schramm (1977). Recent observations of type Ia supernovae at high redshift (Riess et al. 1998, Perlmutter et al. 1999), which imply either an accelerating universe or an unrecognized cause for dimming of the supernova light, have renewed interest in intergalactic dust. Aguirre & Haiman (2000) calculated the contribution such dust would make to the CIB, assuming it were heated by the ambient intergalactic radiation field and sufficiently abundant to account for the dimming of the distant supernovae. They found that such dust would produce most of the observed CIB at 850 µm. However, discrete sources detected by the SCUBA survey account for almost all of the CIB at this wavelength, leaving little room for any diffuse emission component and implying insufficient intergalactic dust to account for the supernova dimming.